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MACHINE 

PRACTICE 


AN    INSTRUCTIVE,  ILLUSTRATED   MANUAL   ON 

MOLDER  WORK— THE  OPERATION  AND 

SUPERINTENDANCE  OF  THE 

MOLDING  MACHINE 


BY 


W.   H.   ROHR 

PROFESSIONAL  WRITER  ON  MACHINE 
WOOD-WORKING 


12.50 


INDIANAPOLIS 

PRACTICAL  BOOKS  CO. 

INDIANA 


-f 


Copyright,  1919,  The  Practical  Books  Co. 

All  Rights  Reserved. 
Published  November,  1919. 

A tfric,- Forestry.  Main  Library 


PREFACE. 


Several  years  previous  to  the  publishing  of  this  book,  the 
riter,  then  a  practicing  woodworker,  was  firmly  convinced 
that  a  manual  on  molder  practice  would  be  welcomed  by 
thousands  of  machine  woodworkers  who  possess  only  the 
limited  knowledge  acquired  by  years  of  experience  in  a 
single  or  several  establishments. 

Holder  work  involves  many  operations  and  considerable 
technique.  A  book  which  would  lack  any  of  the  details  or 
variety  of  modern  methods  used  in  all  kinds  of  woodwork- 
ing plants  would  be  incomplete  and  of  limited  value  to  the 
trade  in  general. 

Undoubtedly  the  previous  absence  of  such  a  work  as  this 
is  accountable  for  in  the  fact  that  to  produce  a  compre- 
hensive treatise  most  likely  to  meet  the  requirements  of  the 
greatest  number  of  persons  meant  months  of  traveling  for 
the  author,  and  consultation  with  hundreds  of  practical 
men  over  the  country  in  order  to  uncover  and  separate  the 
most  modern  and  efficient  methods  in  use. 

Fortunately,  the  writer  has  had  just  such  an  opportunity 
to  gather  material  for  this  book,  hence  the^  knowledge  dis- 
closed in  the  subsequent  pages  has  been  verified  by  personal 
observation  and  practical  experience. 

No  attempt  is  made  to  establish  in  each  case  set  rules  for 
the  subject  treated.  Unusual  conditions  require  special 
treatment,  and  in  numerous  occasions  one  may,  even  with 

•27 


4     ^  \  M^CilLNE  HOLDER  PRACTICE. 

4he  aid  of  this  book,  he^on'ipelled  to  lean  upon  his  own  skill 
1  in  solving  the  problems  of  his  work.    Some  of  the  principles 
and  practical  details,  while  superfluous  to  the  expert,  are 
included,  however,  for  the  general  class. 

The  author  desires  to  record  in  these  pages  special  ac- 
knowledgement of  the  assistance  rendered  him  by  Mr.  G-.  H. 
Oburn,  and  to  machinery  manufacturers  who  permitted  the 
illustrating  of  their  molders  and  equipment.  Thanks,  too, 
for  the  courtesies  extended  to  me  by  friends  thruout  the 
United  States  whose  suggestions  and  practical  ideas  assisted 
in  making  possible  this,  the  first  work  on  molder  practice. 

W.  H.  EOHB. 


CONTENTS. 


CHAPTEE  I. 
The  Alignment  of  a  Holder 9 

CHAPTEE  IT. 
Planning  Set-Ups  and  Selecting  Knives 15 

CHAPTEE  III. 
Balancing  Molder  Knives 23 

CHAPTEE  IV. 
Setting  Up  a  Molder 27 

CHAPTEE  V. 
Making  Under-Cuts  and  Dovetail  Grooves 36 

CHAPTEE  VI. 
The  Use  of  Special  Guides  and  Forms 41 

CHAPTEE  VII. 
Eunning  Molding  Face  Down 55 

CHAPTEE  VIII. 
Special  Surfacing  and  Milling  Knives.  .•. 59 

CHAPTEE  IX. 
Braces  and  Knives  for  Heavy  Work 65 

CHAPTEE  X. 
Making  Moldings  in  Multiples 75 


6  M^Cm-XE  HOLDER  PRACTICE. 


XL 

Miscellaneous  Holder  Work  ........................   86 

CHAPTER  XII. 
High-Speed  Holder  Work  .........................   93 

CHAPTER  XIII. 


Knife  Haking 


CHAPTER  XIV. 
Babbitting  High-Speed  Bearings  ...................  136 

CHAPTER  XV. 
Belting  and  Installing  Holders  .....................  142 

CHAPTER  XVI. 
Holding  Shapes  .................................  151 


MOLDER  PRACTICE. 


CHAPTEK  I. 

THE   ALIGNMENT   OF  A   MOLDER. 

The  four-sided  molder  has  held  an  important  place  in 
the  wood-working  industry  ever  since  wood-working  ma- 
chines came  into  general  use.  Today  the  modern  im- 
proved molder  is  a  greatly  used  machine  in  most  factories 
manufacturing  wood  products;  in  fact,  it  is  absolutely  in- 
dispensable in  establishments  making  interior  and  exterior 
wood  trim,  fixtures,  show  cases,  cabinets,  furniture,  pianos, 
picture  frames,  caskets,  incubators,  harvesting  machines 
and  other 'agricultural  implements,  street  and  railway  cars, 
toys  and  novelties,  etc. 

Altho  the  bulk  of  the  work  done  on  an  ordinary  molding 
machine  consists  of  moldings  or  molded  work  of  different 
kinds,  the  machine's  usefulness  is  not  limited  to  this  class 
of  work.  A  molder  can  be  set  up  to  perform  such  oper- 
ations as  plain  surfacing,  gang  ripping,  plain  milling,  glue 
jointing  and  some  kinds  of  irregular  shaping. 

It  is  a  most  interesting  machine.  To  operate  a  molder  or 
to  even  stand  near  one  and  observe  how  rough  stock  enters 
the  rolls,  passes  thru  the  machine  and  comes  out  so 
smooth  and  nicely  molded,  or  milled  to  shape,  is  indeed, 
fascinating.  It  is  this  fascination  that  has  lured  many  am- 
bitious and  mechanically-inclined  young  men  to  choose 
molder  work  as  their  vocation.  The  molder  appeals  to  the 
average  young  man,  more  so,  perhaps,  than  any  other 
wood-working  machine  because  the  work*  gives  opportunity 
to  display  his  mechanical  ability,  and  it  possesses  enough 
variety  to  make  it  both  agreeable  and  intensely  interesting. 

There  are  many  things  to  know  about  molder  work,  and 
heretofore  there  have  been  so  few  occasions  to  learn  even  a 
fair  part  of  them  thoroly  that  today  there  is  a  scarcity  of 
first-class  moldermen — men  who  can  put  a  molder  in  good 


MACHINE  HOLDER  PRACTICE. 


THE  ALIGNMENT  OF  A  MOLDER. 


11 


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12  MACHINE  HOLDER  PRACTICE. 

order,  keep  it  in  perfect  repair,  make  and  temper  cutters, 
and  set  up  accurately  and  quickly  for  any  kind  of  molding 
or  milled  work. 

The  care  and  operation  of  a  molder  should  be  learned 
fchoroly,  step  by  step,  beginning  first  with  the  alignment  of 
the  machine.  Correct  machine  alignment  is  a  necessary  re- 
quirement in  the  production  of  good  molding.  No  amount 
of  skill  at  setting  up  or  feeding  the  machine  will  success- 
fully overcome  imperfections  in  the  line-up  of  the  bed, 
guides,  chipbreakers,  feed  rolls,  etc.  It  is  the  imperfect 
alignment  of  some  parts  of  the  machine  that  causes  a  great 
deal  of  apparently  mysterious  molder  trouble.  Testing  and 
adjusting  the  line-up  of  a  molder,  when  necessary,  is  a 
comparatively  simple  matter  if  once  clearly  understood.  A 
long  and  short  straight  edge,  a  steel  square,  and  wrenches  to 
make  adjustments  are  needed  before  starting. 

Begin  by  testing  and  leveling  up  the  bed.  See  that  the 
bed  plates  opposite  the  side  heads  are  neither  too  high  nor 
too  low,  and  that  the  rear  table  back  of  the  bottom  head 
lines  up  with  the  main  bed  lengthwise,  and  that  crosswise  it 
lines  with  the  cutting  circle  of  the  bottom  head.  Level  the 
lower  feed  rolls  with  the  bed  and  let  their  upper  faces 
come  above  the  bed  just  enough  to  relieve  the  friction  of 
stock  as  it  passes  over  the  bed  under  the  top  infeed  rolls. 
The  first  bottom  roll  should  be  set  slightly  higher  than  the 
second  to  permit  the  stock  to  feed  straight  into  the  machine 
without  cramping  or  bending.  The  exact  amount  of  eleva- 
tion recommended  for  the  lower  rolls,  see  dotted  line  A  in 
Fig.  1,  will  depend  upon  the  kind  of  stock  generally  run, 
and  whether  it  is  surfaced  or  run  in  the  rough.  Ordinarily 
the  second  roll  is  given  1/32  to  1/16-in.  elevation  above  the 
bed  and  the  first  roll  is  set  slightly  higher. 

As  to  the  guides,  those  parts  which  form  the  inside  guide 
or  guide  rail  from  the  infeed  end  of  the  machine  to  the 
inside  head  I,  are  the  only  really  permanent,  stationary 
guides  on  a  molder  (all  others  are  adjustable  as  occasion 


THE  ALIGNMENT  OF  A  HOLDER,  13 

requires,  to  the  finished  width  of  the  molding)  therefore, 
they  must  be  lined  with  special  care.  When  they  are  ad- 
justed to  a  perfectly  straight  line  from  end  to  end,  and  set 
square  with  the  top  head,  the  bolts  should  be  set  down  tight 
so  that  no  part  of  the  guide  rail  can  possibly  shift  or  move 
out  of  position. 

By  studying  the  line-up  of  the  feed  rolls  in  the  plan  of 
Fig.  1,  it  is  apparent  that  they  are  not  set  perfectly  square 
with  the  guide  rail.  A  slight  forward  lead  is  given  them  so 
that  the  stock  feeding  thru  the  machine  will  have  a  ten- 
dency to  always  feed  tightly  up  to  the  guide  rail.  This  is 
an  important  detail.  It  assists  the  machine  feeder  won- 
derfully, especially  when  he  has  crooked  lumber  or  short 
lengths  of  wide  material  to  run.  All  molding  machines 
do  not  permit  of  this  adjustment  but  on  the  later  types  of 
molders  the  adjustment  is  generally  possible.  When  the 
rolls  are  set  in  this  manner  it  is  unnecessary  to  put  exces- 
sive tension  upon  the  side  springs,  or  to  employ  extra 
levers  and  devices  to  hold  the  stock  up  tightly  to  the  guide 
rail. 

The  top  head  chipbreaker  C,  and  the  side  head  chip- 
breaker  S,  should  be  adjusted  to  swing  in  a  little  past  line 
with  the  cutting  circles  described  by  the  top  and  outside 
heads  respectively,  so  that  both  will  hold  the  stock  firmly 
in  place  even  tho  it  be  a  little  under  size  in  places. 

It  is  also  apparent  in.  Fig.  1,  that  the  inside  ends  of  the 
top  and  bottom  heads  are  set  a  fraction  of  an  inch  "in" 
past  the  line  of  the  guide  rail,  and  similarly  the  lower 
ends  of  both  side  heads  fall  a  little  below  the  bed  line.  This 
is  done  purposely  to  permit  of  bolting  overhanging  mold- 
ing cutters  close  to  the  ends  of  the  heads,  and  when  the 
heads  are  so  positioned  to  suit  the  operator,  they  should 
be  marked  and  not  shifted  from  their  position  unless  abso- 
lutely necessary. 

The  side  head  spindles  should,  of  course,  set  plumb  with 
the  machine  bed,  and  the  top  and  bottom  heads  should  line 


14  MACHINE  MOLDER  PRACTICE. 

parallel  with  it.  If  they  do  not,  the  defect  should  be  cor- 
rected or  the  amount  they  are  "out"  should  be  carefully 
measured  so  that  it  can  be  taken  into  account  when  making 
set-ups  or  adjusting  the  molder  gage. 

With  these  suggestions,  any  molder  can  be  lined  up  cor- 
rectly, and,  in  the  language  of  shop,  the  molderman  "knows 
where  he  is."  Operation  can  then  begin  with  the  assurance 
that  the  machine  is  in  condition  to  turn  out  first-class 
molding  insofar  as  alignment  is  concerned. 


Typical    square,    slotted    cutterhead   fitted   with    ordinary 
straight  surfacing  knives  made  of  carbon  steel. 


CHAPTEE  II. 

PLANNING  SET-UPS  AND  SELECTING  KNIVES. 

When  ready  to  set  up  a  molder  for  any  kind  of  work,  first 
examine  the  drawing  or  sample  furnished,  then  plan  the 
set-up  accordingly.  The  golden  rule  to  observe  is  to  choose 
the  quickest  and  easiest  method  by  which  smooth,  accurate 
molding  can  be  produced  with  safety.  The  best  way  to  han- 
dle any  particular  job  is  always  governed  by  such  local  con- 
ditions as  the  size  and  kind  of  machine  and  cutters  avail- 
able, amount  of  molding  to  be  run,  the  kind  and  condition 
of  stock,  whether  soft  or  hardwood,  wet,  green,  semi-dry  or 
kiln  dried,  surfaced  or  unsurf  aced,  etc. 

All  stock  for  moldings  should  be  thoroly  kiln  dried  be- 
fore it  is  worked  and  all  hardwoods  for  high-grade  finish 
moldings  should  be  surfaced  before  being  put  thru  the 
molder.  Softwood  may  be  run  in  the  rough,  but  if  high- 
grade  finish  is  required,  it  is  best  to  have  the  stock  planed 
first,  unless  it  is  to  be  manufactured  into  molding  on  a 
modern  five- head  or  six-head  molder  having  straight  planer 
heads  at  the  front  and  molding  profile  heads  at  the  rear 
end. 

An  expert,  when  acquainted  with  his  machine  and  the 
conditions  which  prevail  where  he  works,  can  tell  the  in- 
stant he  sees  the  outlines  of  any  ordinary  molding  just  how 
he  is  going  to  make  it.  A  less  experienced  man,  however, 
must  give  a  little  time  to  studying  it  out. 

Moldings  are  now  run  both  face  up  and  face  down,  but 
the  old-established  practice  is  to  make  them  face  up,  there- 
fore the  face-up  method  will  be  discussed  now,  and  the 
face-down  system  explained  in  Chapter  VII.  All  of  the 
early  four-side  molders  were  designed  to  work  the  face  side 
of  molding  with  the  top  head,  the  edges  with  the  side  heads, 
and  the  back  with  the  bottom  head,  and  this  is  the  way 


16 


MACHINE  HOLDER  PRACTICE. 


moldings  are  worked  at  the  present  time  in  a  large  number 
of  factories. 

Another  well-established  practice  which  has  been  handed 
down  by  pioneers  in  the  trade  is  to  work  the  thick  edge  of 
moldings  next  to  the  guide  rail,  and  this  is  usually  the 
best  plan  even  in  light  of  modern  methods,  unless  one  has  to 
run  two  or  more  different  widths  having  exactly  the  same 
molded  side  and  edge,  as  for  example,  round-edge  casings, 
chair  rail,  apron,  base,  etc.  In  the  latter  case  the  molded 
edge  should  be  run  next  to  the  guide  rail  regardless  of 


Fig.   2.     M,  wide,   solid  knife.     S,   T,   R,    sectional  knives  for 
combination  set-up. 

whether  it  is  thick  or  thin,  so  the  knives  will  not  have  to  be 
shifted  or  changed  when  the  machine  is  changed  to  suit 
different  widths  of  the  same  style  of  molding.  With  this  in- 
formation it  is  apparent  that  moldings  similar  to  the  one 
shown  in  Fig.  2  should  be  run  with  the  molded  side  up  and 
the  thick  edge  to  the  guide  rail.  The  edge  will  be  sur- 


PLANNING  SET-UPS  AND  SELECTING  KNIVES. 


17 


faced  with  the  side  heads  and  if  the  stock  has  not  been 
previously  planed,  the  back  must  be  dressed  with  the  bot- 
tom head. 

If  a  rabbett  is  required  as  indicated  by  dotted  lines  at  A, 
it  can  be  cut  with  knives  either  on  the  inside  head  or  bottom 
head.  A  bevel,  cove  or  quarter-round  can  be  made  at  this 


Fig.   3. 


Patterns  with  thin  edges  are  often  worked  with 
the  top  head. 


corner  in  the  same  manner,  but  in  most  cases  it  is  best  to 
use  the  bottom  head  for  such  work  because  it  is  more  ac- 
cessable,  has  greater  belt  power,  and  there  is  more  clearance 
for  the  sweep  of  cutters.  Tongues  and  grooves  and  certain 
other  shapes,  however,  can  only  be  worked  on  the  edges  with 
the  side  heads.  When  a  rabbett  is  made  in  such  manner 
that  a  very  thin  edge  is  left  on  the  molding,  as  at  B,  Fig.  2, 
the  rabbett  should  be  worked  with  the  side  head  instead  of 
the  bottom  head.  Otherwise,  the  thin  remaining  edge 
would  probably  be  broken  off,  or  at  least,  badly  chipped 
and  split  away  in  places. 

When  a  pattern  tapers  down  to  a  comparatively  thin  edge 
as  at  J,  K,  L  and  0,  Fig.  3,  it  is  generally  better  to  leave 
the  outside  head  idle,  or  both  side  heads  if  both  edges  are 
thin,  and  finish  the  edge  as  well  as  the  face  of  the  molding 
with  the  top  head,  provided  the  stock  is  not  more  than 
1%-in.  thick.  It  is  usually  dangerous  to  cut  down  thru 
stock  thicker  than  1%-in.  with  ordinary  cutters. 


18  MACHINE  HOLDER  PRACTICE. 

Double  beveled  edges  like  those  on  crown  moldings,  see 
Fig.  4,  are  made  with  knives  on  the  top  and  bottom  heads 
whenever  possible — rarely  with  the  side  heads.  However, 
when  making  patterns  like  this  the  outside  head  (carrying 
straight  knives)  is  used  to  size  the  stock  to  a  uniform  width 
so  that  it  will  advance  properly  between  close-fitting  guides 
to  the  bottom  head,  where  the  final  cut  is  made.  Compara- 
tively thin  moldings,  13/16-in.  or  less,  are  often  sized  to 
width  with  a  pair  of  sizing  knives  on  the  top  head. 

A  point  worth  remembering  in  planning,  work  ahead  at 
the  molder  is  the  possibility  of  saving  time  and  labor  by 
grouping  the  work  according  to  its  kind  and  size.  Hard- 
wood moldings  and  those  containing  deep,  heavy  cuts  are 
run  at  slow  feeds  and  often  with  special  cutters,  therefore 
these  should  be  grouped  whenever  possible.  Likewise  there 
can  be  a  grouping  of  widths  and  thicknesses  and  patterns  of 
the  same  profile.  This  always  helps  to  materially  reduce 
the  amount  of  work  necessary  in  changing  a  machine  from 
one  pattern  to  another. 

SELECTING    KNIVES. 

The  types  of  molding  knives  commonly  used  on  square 
heads  consist  of  slotted  knives,  see  M  and  R,  Fig  2;  spike 
knives,  S  and  T,  Fig.  2;  milled-to-pattern  slotted  knives, 
X,  Fig.  5 ;  thin  high-speed  steel  knives  under  caps,  Y  and 
Z,  Fig.  5.  Wide  slotted  knives,  made  of  either  solid  or 
laid  carbon  steel,  are  the  old-fashioned  type  and  are  still 
used  in  many  plants.  At  one  time  it  was  the  universal 
custom  to  make  a  pair  of  wide  knives  for  each  pattern  of 
molding,  but  this  slow,  expensive  practice  has  been  largely 
superseded  by  what  modern  moldermen  call  the  combina- 
tion set-up  in  which  several  narrow  knives  are  combined  to 
make  any  required  cut.  The  latter  is  by  far  the  better 
method  to  use  when  a  large  variety  of  moldings  are  manu- 
factured, and  it  is  often  the  best  on  stock  work.  Some  of 
the  chief  reasons  why  the  wide  solid  knives  have  been 


PLANNING  SET-UPS  AND  SELECTING  KNIVES. 


19 


abandoned  are,  because  they  are  expensive  in  first  cost,  diffi- 
cult to  make,  and  when  once  made  they  are  hard  to  keep  in 
shape  and  sharpen.  Each  wide  knife  is  only  good  for  one 
pattern  of  molding.  Take  the  knife  M,  Fig.  2,  for  ex- 
ample; it  cannot  be  used  to  make  any  other  pattern,  hence 


Fig\  4.     Showing   how    sectional    cutters   should   be   arranged. 

its  usefulness  is  very  limited.  It  contains  two  corners 
which  can  be  reached  only  with  a  three-cornered  file,  thus 
necessitating  a  filing  temper  which  will  not  hold  a  sharp 
edge  very  long.  In  the  process  of  resharpening,  this  knife 
will  gradually  wear  wider  between  the  corners  that  are 
filed,  and  in  doing  so  it  loses  its  original  shape.  If  a  small 
nick  developes  at  any  point,  the  entire  edge  must  be  re- 
ground  and  filed  in  order  to  preserve  the  same  general 
profile. 

Narrow  knives,  on  the  other  hand,  are  less  expensive  in 
first  cost,  easier  to  make,  and  can  be  so  designed  that  all  in- 
side corners  are  eliminated,  thus  permitting  the  entire  edge 
to  be  sharpened  on  a  grinding  wheel.  This  feature  allows 
using  a  harder  temper,  which  holds  a  keen  edge  longer,  and 
makes  it  possible  to  keep  the  knives  in  correct  shape  in- 


20  MACHINE  HOLDER  PRACTICE. 

definitely.  Narrow  knives  also  have  the  important  ad- 
vantage of  being  readily  adapted  to!  a  wide  range  of  work 
on  a  variety  of  patterns.  Another  point  in  their  favor  is 
that  by  breaking  up  a  wide,  complicated  cut  with  several 
narrow  knives  (see  S,  T  and  K,  Fig.  2,  and  A,  B,  C,  D,  etc., 
Fig.  4)'  distributed  around  on  different  sides  of  the  head, 
there  is  less  strain  on  the  bolts  and  a  better  balanced  and 
an  easier-running  cutting  unit  is  provided.  The  result  is  a 
smoother  finish  and  less  chipping  of  the  grain. 

A  large  assortment  of  narrow  knives  is  extremely  valu- 
able in  plants  manufacturing  odd  and  special  work  be- 
cause the  same  knives  can  be  used  repeatedly  in  different 
combinations  to  cut  all  sizes  and  shapes  of  molding.  New 
patterns  can  be  worked  and  obsolete  ones  frequently 
matched  without  making  or  changing  a  cutter.  The  neces- 
sary combinations  are  simply  built  up  with  the  knives  at 
hand.  Narrow  knives  should  be  grouped  in  the  racks  ac- 
cording to  shape  and  size.  An  assortment  for  general  work 
will  include  a  large  variety  of  quarter  and  half-rounds, 
coves,  beads,  ogees,  reverse  ogees,  bevels,  surfacers,  grooving 
and  rabbetting  cutters,  quirks,  etc. 

Spike  knives  like  S  and  T,  Fig  2,  are  made  from  long 
bars  of  carbon  or  self -hardening  steel,  %  to  5/16-in.  thick. 
Often  they  are  spread  at  the  end  to  make  a  wider  cut.  They 
are  fastened  to  the  head  under  square  steel  caps  or  washers 
about  i/i-in.  thick,  see  Fig.  7,  Chapter  IV.  Two  spikes 
must  be  placed  under  a  plain  cap  like  that  in  Fig.  7,  but 
caps  can  be  made  with  one  edge  bent  over  or  offset  in  such 
a  manner  that  the  shoulder  will  take  the  place  of  the  slug 
shown  in  Fig.  7.  Caps  of  the  latter  type  are  especially  good 
for  side  heads  where  there  is  seldom  any  call  for  more  than 
one  molding  knife  on  each  side  of  the  head. 

Milled  knives  like  X,  Fig.  5,  may  be  purchased  from 
stock  or  made  in  the  grinding  room  on  a  modern  head- 
grinding  machine.  The  profile  of  the  mold  is  milled  in 
the  back,  and  a  face  bevel  is  ground  on  the  front  as  shown. 


PLANNING  SET-UPS  AND  SELECTING  KNIVES  21 


Fig.  5.     X  is  milled  knife  with  front  bevel.     Y  and  Z  show  thin 
steel  knives  under  caps. 


22  MACHINE  HOLDER  PRACTICE. 

The  knife  is  sharpened  by  grinding  the  flat  face-bevel.  In 
some  cases  a  strip  of  high-speed  steel  is  brazed  onto  the 
front  beveled  face,  as  shown  by  dotted  lines  at  X,  Fig.  5, 
in  order  to  give  a  harder  and  longer-lasting  cutting  edge. 
The  advantages  of  milled  knives  are  that  they  retain  their 
correct  shape  until  worn  out,,  are  easily  sharpened,  produce 
very  smooth  work  on  kiln-dried  stock,  and  never  tear  out 
cross  grain.  On  the  other  hand,  their  usefulness  is  limited 
to  comparatively  light  cuts  and  considerable  more  power  is 
required  to  drive  them  thru  the  stock.  Knives  of  this  type 
are  used  in  a  great  many  mills  in  the  Pacific  Northwest 
for  working  bone-dry  fir. 

The  cutter  shown  at  Y,  in  Fig.  5  consists  of  an  ordinary 
slotted  knife,  milled  as  shown,  to  receive  a  narrow  strip  of 
high-speed  steel.  The  chief  purpose  of  this  kind  of  combi- 
nation is  to  utilize  thin-steel  knives  that  are  worn  too  nar- 
row for  further  use  as  surfacing  knives.  The  narrow  cut- 
ters are  particularly  adapted  to  making  beads  and  V?s  on 
beaded  and  Y-ceiling,  also  other  light,  narrow  cuts  of  a 
similar  nature. 

Still  another  method  of  using  thin  high-speed  steel  on 
square  slotted  heads  is  shown  at  Z.  High-speed  steel  cut- 
ters will  hold  an  edge  for  a  long  time  and  are  quite  satis- 
factory for  relatively  light  cuts.  They  are  often  made 
from  broken  planer,  matcher  or  jointer  knives,  altho  in 
some  plants,  regular  high-speed  bar  steel  is  purchased  for 
making  small  molding  and  spike  knives.  IJnlike  carbon 
steel,  high-speed  steel  requires  no  heat  treatment  before 
using. 


CHAPTER  III. 

BALANCING    HOLDER    KNIVES. 

Correct  knife  balance  is  one  of  the  most  important  fac- 
tors in  molder  work.  Every  molderman  who  expects  to 
produce  high-grade  molding  and  keep  his  machine  in  good 
running  order,  with  the  least  amount  of  trouble  and  ex- 
pense, should  exercise  particular  care  and  good  judgment 
in  balancing  the  cutters. 

It  is  a  well-known  mechanical  axiom  that  any  object  re- 
volving at  high  speed  must  be  in  a  perfect  state  of  balance 
to  proceed  smoothly  and  safely  without  vibration.  This  is 
especially  true  of  the  cutterheads  on  molding  machines,  as 
they  run  from  3,000  to  4,000  r.p.m.,  and  any  slight  devia- 
tion from  a  perfect  running  balance  produces  a  violent  jar, 
causing  the  bearings  to  heat,  hence  a  wavy  finish  on  the  sur- 
face of  the  molding.  There  are  at  least  four  kinds  of  bal- 
ance that  must  be  observed  when  balancing  a  set  of  knives : 
dead-weight,  line,  projection  and  thickness  balance.  Theo- 
retically, the  knives  on  opposite  sides  of  a  cutterhead  should 
pair  exactly  in  dead- weight,  in  thickness  and  in  projection, 
and  they  should  be  in  perfect  line  directly  opposite  one  an- 
other on  the  head.  It  is  quite  possible  to  keep  straight 
dressing  knives  and  some  molding  knives  in  this  theoreti- 
cally ideal  alignment,  but  when  using  sectional  knives  it 
is  more  often  impossible  and  even  undesirable  to  always 
have  them  paired  in  this  manner. 

In  actual  practice,  especially  in  factories  turning  out  odd 
detail  work  where  frequently  twenty  or  more  set-ups  are 
made  in  a  day  on  a  machine,  there  is  seldom,  if  ever,  more 
than  one  knife  used  for  each  member  of  the  molding.  As  a 
result,  a  knife  that  cuts  one  member  is  balanced  by  one  that 
cuts  another  member,  or  by  a  "dead"  knife  bolted  opposite 


24 


MACHINE  HOLDER  PRACTICE. 


to  it.  Eight  here  it  might  be  well  to  explain  that  on  short 
runs  there  is  no  advantage  in  bolting  a  pair  of  knives 
shaped  exactly  alike  onto  opposite  sides  of  the  heads  with 
the  expectation  that  both  knives  will  cut  alike  and  conse- 
quently produce  smoother  work  than  one,  because  it  is 


Fig-.  6. 


G,  knives  set  in  staggered  fashion, 
staggered  effect. 


H  and  I,  correcting 


practically  impossible  to  set  two  knives  to  cut  alike.  They 
can  be  made  to  cut  alike  by  jointing  at  full  speed  or  by  re- 
peatedly whetting  the  knife  that  sets  out  the  farthest,  but 
this  is  only  profitable  on  long  runs. 

To  successfully  balance  sectional  knives  one  must  strive 
to  become  an  expert  at  balancing,  which  he  can  do  by  using 
good  judgment  and  observing  the  tried-and-tested  rules  of 
knife  balance.  Perfection- in  balancing  is  only  acquired  by 
experience,  but  the  following  rules  will  serve  as  a  valuable 
guide: 


BALANCING   MOLDER   KNIVES.  25 

Eule  1.  When  necessary  to  mate  two  knives,  one  of 
which  must  be  set  out  farther  than  the  other,  the  knife 
projecting  the  farthest  should  be  the  lightest  in  dead 
weight.  Any  deficiency  in  weight  in  the  short  knife  can  be 
made  up  by  using  an  extra  washer  or  heavier  bolt,  or  by 
slipping  a  slug  of  metal  in  the  bolt  slot  under  the  short 
knife.  It  is  always  a  good  plan  to  keep  a  number  of  wash- 
ers and  weight  slugs  of  different  sizes  on  hand  for  use  in 
'  forcing  a  balance  in  emergencies.  The  same  methods  are 
followed  to  produce  a  balance  when  one  knife  is  thicker  or 
heavier  than  its  mate. 

Eule  2.  The  center  of  weight  of  a  pair  of  knives,  bolted 
to  opposite  sides  of  a  cutterhead,  should  come  exactly  in 
line.  In  other  words,  no  pair  of  knives  should  be  set  in 
staggered  fashion  as  shown  at  G,  Fig.  6.  In  practice  this 
rule  cannot  always  be  followed  to  the  letter,  so  the  next 
best  thing  under  adverse  conditions  is  to  observe  Eule  3. 

Eule  3.  The  center  of  weight  of  a  group  of  knives,  bolted 
to  opposite  sides  of  the  head,  must  come  absolutely  in  line 
to  maintain  the  running  balance  of  the  cutterhead.  This 
latter  rule  is  a  hard  and  fast  one — there  is  no  getting 
around  it.  However,  it  permits  setting  a  pair  of  knives  in 
staggered  fashion  on  condition  that  suitable  weights  or  an 
extra  knife  or  set  of  knives,  as  required,  are  so  placed  as  to 
counteract  the  staggered  effect  and  bring  the  center  of 
weight  on  opposite  sides  of  the  head  in  line,  see  H,  Fig.  6. 
One  more  method  to  counteract  the  effect  of  staggered 
knives  appears  at  I,  Fig.  6. 

Eule  4.  Still  another  point  in  knife  balance  that  should 
be  observed  when  using  sectional  cutters  ?s  to  distribute  the 
cutting  knives  around  the  head  as  evenly  as  possible.  In 
other  words,  do  not  bolt  all  the  knives  on  one  side  of  the 
head  and  the  balance  weights  on  the  other  side.  Likewise, 
do  not  bolt  all  the  knives  that  cut  heaviest  on  one  side,  and 
those  that  cut  lightest  on  the  other  side  if  it  can  be  avoided. 
Furthermore,  when  running  a  many-membered  molding, 


<tb  MACHINE  HOLDER  PRACTICE. 

avoid  putting  both  knives,  which  cut  at  or  near  the  outer 
edges  of  the  molding,  on  the  same  side  of  the  head.  Let 
one  edge-knife  come  on  one  side  of  the  head  while  the  other 
comes  on  the  opposite  side  of  the  head.  These  last  points 
are  clearly  illustrated  in  Fig.  4,  Chapter  II.  Here  the  top 
bevel  knives  A  and  D  are  not  placed  on  the  same  side  of 
the  head,  neither  are  the  bottom  bevels  E  and  F.  Knives 
A  and  C  on  one  side  of  the  head  are  balanced  by  B  and  I), 
respectively,  on  the  opposite  side,  while  the  knife  that  cuts 
the  middle  part  is  balanced  by  a  mate  of  the  same  shape 
or  by  any  knife  of  the  right  weight  that  comes  handy. 
Bevels  E  and  F  are  balanced  with  similar  bevels  of  the  same 
general  shape  and  weight,  or  by  any  available  knives  of  the 
required  weight. 


Thin,  high-speed  steel  surfacing  knives  attached  to  square 
head  with  caps  and  bolts. 


CHAPTEE  IV. 

SETTING  UP  A  HOLDER. 

Setting  the  knives  and  adjusting  the  machine  for  a  run 
of  new  molding  are  tasks  that  test  a  molderman's  skill 
and  ability.  It  is  therefore  to  his  interest  to  have  things 
handy  about  the  machine  and  to  practice  a  method  of  set- 
ting up  that  is  at  once  simple,  accurate  and  rapid.  The 
common  mistake  of  some  operators  is  to  proceed  with;  the 
execution  of  their  work  with  no  well-defined  or  systematic 
method,  and  as  a  result,  they  make  a  number  of  false  moves 
and  do  more  or  less  unnecessary  tinkering  at  the  machine 
every  time  they  set  it  up.  These  useless  moves  consume 
valuable  time  and  reduce  efficiency.  Even  by  the  best 
methods  there  are  several  adjustments  to  make  when  set- 
ting up  for  new  work  or  changing  from  one  job  to  another, 
therefore  it  is  apparent  that  a  predetermined  and  efficient 
system  is  very  essential. 

The  first  requisite  for  convenience  in  setting  up  is  to 
have  a  variety  of  wood  pressure  bars  grouped  together  in 
a  rack  near  the  machine.  The  necessary  machine  wrenches 
and  a  long-handled  screw  driver  should  also  have  their 
appointed  places  within  easy  reach.  Extra  knife  bolts 
with  washers  and  nuts,  screws  for  the  pressure  bars,  ham- 
mer, pliers,  bevel  and  try-square,  oil-slip,  wiping  waste 
and  a  few  clean  blank  templets  should  be  kept  in  a  drawer 
near  at  hand. 

The  machine  should  be  fitted  with  .index  plates  and 
pointers  to  show  at  a  glance  just  how  far  to  set  the  top 
head  from  the  bed  of  the  machine  to  cut  a  given  thickness 
and  how  far  to  set  the  outside  head  from  the  guide  rail 
to  cut  a  given  width.  There  should  also  be  marks  to  indi- 
cate the  location  of  the  bottom  and  inside  heads  for  differ- 
ent size  cuts.  It  requires  an  extra  move  and  additional  time 


28  MACHINE  HOLDER  PRACTICE. 

to  measure  machine  adjustments  with  a  rule  and  the 
chances  for  inaccuracy  are  much  greater.  It  is  not  safe  to 
determine  these  distances  by  counting  the  turns  made  with 
the  crank  or  hand  wheel  because  machine  screw  threads 
develop  play  in  time,  and  when  a  screw  is  reversed  it  some- 
times requires  half  a  turn  or  more  before  the  head  will 
move. 

If  the  feed  is  not  under  perfect  control  and  cannot  be 
stopped  instantaneously  with  the  feed  lever,  a  simple  quick- 
acting  brake  of  home-made  construction  should  be  added 
for  this  purpose.  It  is  also  helpful,  if  quick  machine  stops 
are  desired,  to  add  a  brake  to  the  machine  countershaft 
because  the  natural  momentum  of  any  smooth-running 
molder  will  often  cause  the  cutterheads  to  continue  in  mo- 
tion for  some  time  after  the  power  has  been  turned  off. 
The  blower  pipes  connected  to  the  hoods  should  be  arranged 
to  telescope  or  swing  out  of  the  way  in  such  a  manner  that 
they  will  not  have  to  be  replaced  every  time  the  operator 
changes  or  sets  the  knives  on  a  head. 

To  proceed  in  setting  up  be  sure  to  have  all  knives,  etc., 
selected,  balanced,  and  laid  out  carefully  before  you  be- 
gin to  put  them  on  the  heads.  Then  make  it  a  point  to 
set  each  head  complete  as  you  go;  for  example,  start  with 
the  top  head,  and  follow  in  regular  order  to  the.*  outside 
head,  inside  head  and  finally  the  bottom  head.  By  adopt- 
ing and  adhering  to  a  systematic  routine  of  this  sort  the 
work  soon  becomes  easy  and  natural,  and,  one's  movements 
get  to  be  automatic,  so  to  speak,  resulting  in  remarkable 
speed  and  accuracy. 

There  are  a  number  of  methods  used  and  exploited  for 
positioning  or  setting  knives  on  square  cutterheads,  but 
the  majority  of  uptodate  moldermen  thruout  the  coun- 
try use  the  molder  rule  in  some  form  for  this  purpose. 
Molder  rules  made  of  metal  or  celluloid  can  be  bought  for 
a  nominal  price,  but  if  one  prefers  he  can  make  a  rule,  be- 
ing careful,  however,  to  leave  off  all  patented  features  of 


SETTING  UP  A  MOLDER. 


rules  now  on  the  market.  The  ordinary  molding  rule  is 
lined  off  in  %-in.  divisions  both  ways,  see  Fig.  7,  but  the 
eighths  by  which  the  projection  or  overhang  of  the  knives 
is  measured  are  longer  than  true  %-in.  divisions.  The 
reason  for  this  is  that  a  molder  knife  bolted  to  a  square 


Fig.  7.     Method  of  using1  molder  or   "sticker man's"   rule.     A  is  in 
line  with  guide  rail.     B  is  in  line  with   inside  head. 
«       S  is  surfacing  line. 

• 

cutterhead  strikes  the  work  and  does  its  cutting  at  an  angle 
which  varies  according  to  the  size  of  the  head  and  amount 
of  knife  projection. 

Eeferring  to  Fig.  7,  line  S,  on  the  rule,  is  the  surfacing 
line  to  which  the  cutting  edge  of  the  straight  surfacing 
knives  is  set.  The  edge  of  the  rule  rests  against  the  lip  of 


30  MACHINE  HOLDER  PRACTICE. 

the  head,  and  surfacing  line  S  is  scribed  parallel  to,  and 
about  3/32-in.,  or  %-in.  from  this  edge.  A  knife  edge  or 
point  set  up  to  the  next  line  above  the  surfacing  line  will 
cut  exactly  ^/g-in.  deep,  and  if  set  to  the  second  line  above 
and  parallel  to  line  S,  it  will  cut  ^-in.  deep,  etc.  Lines 
running  lengthwise  of  the  rule  and  parallel  to  line  S  are 
spaced  to  represent  the  molder  scale,  while  those  crossing 
them  are  spaced  exactly  %-in.  apart.  Line  A  indicates  the 
position  of  the  guide  rail,  and  the  distance  from  line  A  to  B 
shows  the  amount  allowed  for  the  cut  of  the  inside  head, 
therefore  the  width  and  location  of  cuts  to  be  made  by 
knives  on  the  top  head  are  measured  from  line  B  unless 
the  inside  edge  of  the  molding  requires  no  surfacing,  in 
which  event  the  cuts  must  be  measured  from  line  A.  The 
method  of  using  the  rule  in  actual  practice  is  shown  clearly 
in  Fig.  7.  The  working  edge  of  the  rule  always  rests 
against  the  lip  of  the  head  while  the  end  is  either  butted 
against  a  convenient  journal-box  casting  as  shown  or  ar- 
ranged to  hook  over  the  end  of  the  cutterhead  as  indicated 
by  dotted  line.  The  former  method  is  recommended  when 
the  construction  of  the  machine  permits  its  use,  because 
when  the  rule  rests  against  an  immovable  casting,  the  head 
can  be  shifted  laterally  either  way  by  the  adjusting  wheel 
without  moving  the  rule,  consequently  any  lateral  shifting 
does  not  destroy  the  alignment  of  line  A  with  the  guide  rail 
nor  line  B  with  the  inside  head.  On  the  other  hand,  if  the 
rule  is  hooked  over  the  end  of  the  head  the  relative  position 
of  the  head  must  always  remain  the  same.  If  shifted,  the 
rule  will  also  move  and  then  require  readjustment  every 
time  to  keep  it  in  correct  alignment  with  the  guide  rail. 

One  of  these  molder  rules  can  be  arranged  to  serve  for 
all  four  heads  on  a  machine  if  so  desired,  but  it  is  much 
easier  and  more  satisfactory  to  use  a  shorter  rule  for  the 
side  heads.  The  principle  of  using  the  rule  on  any  of 
the  other  heads  is  the  same  as  described  for  the  top  head. 
Some  moldermen,  instead  of  using  a  rule  similar  to  that  in 


SETTING  UP  A  HOLDER.  31 

Fig.  7,  use  a  blank  rule  having  only  the  lines  S,  A  and  B. 
On  this  blank  they  locate  the  important  points  of  any 
required  knife  profile  by  using  an  ordinary  rule  and  a  sep- 
arate molder  scale.  The  molder  scale  in  such  cases  is 
sometimes  lined  off  on  a  minature  brass  T-square  which  is 
just  long  enough  to  span  the  width  of  the  blank  rule. 
Sometimes  the  scale  is  marked  off  on  one  edge  of  a  regular 
two-foot,  four-fold  rule.  Others  lay  off  knife  projections  by 
measuring  with  a  common  rule  and  making  proper  allow- 
ance for  the  sweep  of  the  knives.  The  latter  method, 
however,  is  rather  a  hit-and-miss  one,  serving  the  purpose 
fairly  well  but  not-  recommended. 

Another  way  to  set  molder  knives,  and  one  that  is  used 
successfully  by  some  very  fast  set-up  men,  is  to  make  a 
tracing  of  the  molding  upon  transparent  paper  and  then 
fold  and  fasten  this  tracing  in  the  proper  position  on  a 
blank  molder  rule,  as  shown  in  Fig.  8.  Line  L  K  is  drawn 
thru  the  deepest  cut  and  parallel  to  the  face  of  the  mold- 
ing. The  depth  of  this  cut  is  measured  and  then  laid, off 
on  the  rule  according  to  the  molding  scale  as  at  L-l  and 
K-l.  The  tracing  is  then  clamped  to  the  rule  so  that  line 
L-K  comes  exactly  over  line  L-l,  K-l,  and  the  thick  edge 
of  the  molding  comes  exactly  in  line  with  the  inside  head 
cut  as  shown.  Now  the  knife  edge  that  cuts  the  deepest 
member  will  come  right  over  the  line  K-l,  L-l,  as  shown, 
while  the  edge  that  cuts  the  flat  surface  comes  only  to  the 
surfacing  line  S  on  the  blank  rule.  The  remaining  profile 
of  the  molding  knife  falls  below  the  tracing  in  proportion 
to  the  difference  between  the  actual  measurement  and  the 
molder  scale,  as  shown  in  Fig.  8.  • 

A  beginner  on  the  molder  would  probably  not  have  much 
success  with  this  method,  but  an  expert  who  has  a  good  eye 
for  shapes  and  can  tell  at  a  glance  the  exact  allowance  to 
make  between  the  profile  of  a  molding  and  the  correspond- 
ing profile  of  the  knife  edge  to  cut  the  molding,  will  find 
that  this  gives  just  the  guide  needed  for  setting  knives 


32  MACHINE  HOLDER  PRACTICE. 

quickly  and  accurately.  The  method  to  use,  of  course,  is 
largely  a  matter  of  choice  and  the  success  of  any  particular 
system  will  depend  altogether  upon  the  man  who  uses  it. 
The  method  just  described  may  not  appeal  to  some  because 
it  is  not  generally  known  to  the  trade.  However,  molder- 
men  in  some  detail  interior  trim  factories  are  making  re- 
markable speed  with  it,  and  prefer  this  system  to  any  other. 

As  mentioned  at  the  beginning  of  this  chapter,  the 
methods  of  knife,  setting  described  in  the  foregoing  apply 
particularly  to  new  moldings  which  the  operator  has  never 
run.  For  stock  moldings  and  repetition  work  it  is  not 
necessary  to  go  thru  the  process  of  locating  the  required 
position  of  the  knives  on  a  molder  rule  after  the  first  set- 
up has  been  made,  provided  that  set-up  has  been  properly 
"carded,"  or  traced  off  on  blank  templets  and  filed  away  for 
future  use.  Templets  are  undoubtedly  the  best  and  quick- 
est for  setting  up  a  machine  to  make  moldings  which  are 
run  repeatedly.  The  kind  of  templet  recommended  is 
simply  a  blank  rule  made  of  light-colored  wood  or  celluloid 
and,  like  the  molder  rule,  is  arranged  to  either  butt  against 
a  journal  box  casting  as  in  Fig.  7,  or  hook  over  the  end  of 
the  head  as  in  Fig.  8.  After  an  original  set-up  is  made 
correctly,  with  a  molder  rule,  the  outline  and  position  of  the 
knives  as  they  set  on  the  head  are  then  carefully  traced  on 
the  templet  with  a  sharp  pencil.  The  size,  name  and  num- 
ber of  the  molding  are  marked  on  the  templet  or  set  of 
templets,  if  more  than  one  are  necessary  for  a  set-up,  and 
these  are  filed  away  in  regular  order  in  a  rack  or  drawer. 
It  is  a  good  plan  to  shellac  wood  templets  after  they  are 
marked  as  the  shellac  preserves  the  sharp,  clear-cut  lines 
and  keeps  the  templets  clean. 

When  all  knives  are  positioned  on  the  heads,  the  chip- 
breakers  at  the  top  and  outside  heads  must  be  adjusted  to 
swing-in  close  to  the  point  where  the  knives  leave  the  work. 
There  must  be  a  safe  clearance,  of  course,  so  the  tip  of  the 
chipbreaker  will  not  strike  the  points  of  the  knives  or 


SETTING  UP  A  HOLDER. 


33 


swing  into  the  cutting  circle  when  any  over-size  stock  en- 
ters the  machine.  Before  a  piece  is  started  into  the  ma- 
chine the  outer  guides  and  springs  are  pulled  out  to  clear 
it  and  generally  the  blower  hoods  are  left  off  for  the  trial 
start.  The  selection  of  the  first  piece  of  material  to  run 


L 


K 


Fig.  8.     Another  method  of  setting  knives  correctly. 

is  very  important.  It  should  be  full  size,  flat.,  and  perfect- 
ly straight  on  one  edge.  The  straight  edge  is  placed  next 
to  the  guide  rail.  This  piece  is  fed  in  slowly  and  carefully 
to  the  top  head  and  past  it  a  few  inches,  after  which  the  ma- 
chine is  stopped  so  that  a  wood  pressure  bar  can  be  fitted 
to  the  machine  pressure  shoes  and  as  closely  as  possible  to 
the  cutting  circle  of  the  top  head.  Some  moldermen  fit 
the  pressure  bar  to  the  pressure  shoes  before  starting  their 


34  MACHINE  MOLDER  PRACTICE. 

machine  but  this  is  somewhat  risky  because  the  end  of  the 
bar  must  be  high  enough  to  clear  the  advancing  molding 
and  at  the  same  time  be  close  up  to  the  top  head  knives. 
The  least  miscalculation  or  even  the  vibration  of  the  ma- 
chine may  cause  the  knives  to  catch  the  suspended  bar  and 
draw  it  into  the  head  or  hurl  it  back  at  the  operator,  thus 
causing  a  serious  accident.  This  danger  is  not  so  great, 
of  course,  when  running  flat  work.  The  pressure  bar 
should  be  at  least  one-half  to  two-thirds  the  width  of  the 
molding  and  its  underside  should  be  smooth  and  shaped 
to  conform  to  the  general  contour  of  the  molding  so  that  it 
will  perform  its  function  of  holding  the  stock  down  firmly 
to  the  machine  bed  without  marring  the  finished  surface  in 
any  way. 

With  the  pressure  bar  fitted  into  place  and  screwed  down 
lightly,  the  molding  is  fed  past  the  side  heads,  after  which 
the  side  guides  and  rear  end  of  the  pressure  bar  are  ad- 
justed. The  molding  is  then  fed  over  the  bottom  head, 
after  which  the  tail  board  and  the  remaining  guides  are 
adjusted.  For  the  reason  that  considerable  adjusting  is 
necessary  while  the  first  piece  advances  thru  the  machine, 
'it  is  best  to  use  a  piece  of  cheap  scrap  wood  for  the  trial 
set-up  in  order  to  avoid  spoiling  any  good  material.  Even 
after  all  the  knives  are  set  correctly  the  molding  will  often 
fail  to  come  exactly  true  to  pattern  until  the  pressure  bar 
and  all  guides  and  the  tail  board  back  of  the  bottom  head 
are  adjusted  and  secured  firmly  in  position. 

In  all  cases  it  is  important  to  have  the  throat  space  or  gap 
at  the  cutter  heads  as  small  as  possible  so  the  chips  will  be 
broken  off  close  and  so  the  stock  can  neither  spring  up, 
down,  or  sideways.  The  pressure  bar  and  guides  must  not 
be  set  too  tight,  however,  or  the  stock  will  not  feed  freely. 
When  the  molded  end  of  the  trial  piece  is  sticking  out  at 
the  rear  of  the  molder  it  should  be  compared  to  the  sample 
or  drawing  to  make  sure  it  is  correct  in  size  and  shape.  If 
the  machine  has  been  put  in  proper  alignment,  the  molder- 


SETTING  UP  A  HOLDER.  35 

man  has  kept  in  mind  the  relative  position  of  the  heads 
with  the  machine  bed  and  guides,  and  the  molder  rule  has 
been  adjusted  correctly  and  the  set-up  made  faithfully,  as 
recommended  in  this  chapter,  the  molding  will  be  right  at 
the  first  trial.  Otherwise,  more  or  less  adjusting  may  be 
necessary  to  make  it  right.  Here,  let  it  be  emphasized,  is 
where  time  is  lost  and  troubles  begin  if  any  preliminary 
work  has  been  slighted. 

After  the  set-up  is  proved  correct,  the  blower  hoods  are 
then  put  in  place,  the  feed  regulated  if  necessary  and  the 
machine  oiled.  The  operator  can  then  proceed  to  feed  ma- 
terial into  the  machine.  In  feeding,  be  careful  to  observe 
the  direction  of  the  grain  and  look  out  for  defects  in  the 
stock.  The  best  side  must  be  used  to  make  the  face  side  of 
molding  and  the  grain  should  always  be  favored  if  possible, 
so  the  knives  cutting  the  face  of  the  molding  will  not  be 
working  against  the  grain.  Each  piece  of  stock  that  is  fed 
into  the  machine  should  be  butted  squarely  against  the 
piece  preceding  it  and  the  stock  should  be  kept  moving 
forward  while  the  machine  is  in  motion.  The  rate  of 
feed  must,  of  course,  be  regulated  according  to  the  size  of 
the  cut  and  the  kind  of  stock  being  run.  Generally  speak- 
ing, hardwoods  require  a  slow  or  medium  feed  while  soft- 
woods may  be  run  at  a  faster  rate.  In  taking  heavy  cuts 
the  feed  should  be  slower  than  when  taking  light  cuts.  One 
must  rely  largely  upon  his  own  judgment  in  this  matter. 
When  a  large  hard  knot  or  burly  place  is  approaching  the 
knives,  slow  down  the  feed  with  the  lever,  until  the  hard 
place  has  passed  the  cutterheads.  The  yokes,  carrying  cut- 
terheads,  must  be  securely  locked  in  place  so  the  heads  can- 
not shift  or  quiver  while  the  machine  is  in  operation.  The 
tension  on  the  top  feed  rolls  should  only  be  sufficient  to 
carry  the  stock  freely  thru  the  machine,  because  excess  ten- 
sion is  hard  on  the  feed  mechanism.  Experience,  naturally 
acquaints  the  operator  with  numerous  other  little  precau- 
tions to  take  while  operating  a  molder. 


CHAPTEK  V. 

MAKING  UNDER-CUTS  AND  DOVETAIL  GROOVES. 

The  cutting  of  moldings  which  have  members  that  can 
only  be  reached  by  under-cutting  presents  a  different  and 
sometimes  more  difficult  problem  than  is  ever  encountered 
in  making  ordinary  straight-molded  cuts.  Under-cutting 
would  be  almost  impossible  without  special  attachments  if 
it  were  not  for  the  adjustment  on  modern  molders  which 
permits  tilting  the  side  heads  to  any  angle  up  to  about  45 
degrees. 

By  working  a  pattern  face  up  and  cutting  all  of  the  top 
profile  that  can  possibly  be  reached  with  knives  on  the  top 
head,  an  under-cut  member  can  usually  be  reached  with  a 
long,  slender  knife  bolted  to  the  outside  head  when  the 
latter  is  tilted  to  the  proper  angle.  'For  example,  in  Fig. 
9,  the  combined  cornice  and  picture  molding  is  worked  face 
up,  the  top  side  being  almost  finished,  excepting  the  under- 
cut, before  it  reaches  the  side  head,  see  A,  Fig.  9.  This 
leaves  only  a  very  light  under-cut  to  be  finished  with  a 
knife  K  on  the  outside  head  which  must  be  tilted  over  to  the 
angle  shown.  When  a  molding  is  worked  in  this  manner 
the  wood  pressure  bar  must  be  partly  cut  away  just  opposite 
the  outside  head  in  order  to  give  room  for  the  swing  of  the 
long,  overhanging  side-head  cutter  K.  The  moldings  D 
and  E  in  Fig.  10,  which  form  the  sliding  frames  of  one 
kind  of  adjustable  window  screen,  are  worked  in  the  same 
manner  as  just  described,  the  small  under-cuts,  C  C,  being 
made  with  a  knife  bolted  to  the  outside  head,  which  is  tilt- 
ed as  required. 

The  small  under-cut  part  of  window  sills,  Fig.  11,  for 
special  water-tight  frames  can  be  cut  in  this  manner  also, 
provided  the  sills  are  not  too  wide.  A  very  long,  slender 
knife  is  required  to  reach  point  C  on  the  sill.  If  an  under- 


MAKING  UNDER-CUTS  AND  DOVETAIL  GROOVES. 


37 


cut  of  this  kind  cannot  be  reached  with  an  overhanging 
knife  on  a  tilted  sidehead  on  account  of  the  construction  of 
the  machine,  the  usual  alternative  is  to  make  all  cuts  ex- 


FIG.  10 


Figs.  9,  10,   11,   12,   13,    14  and   15   show  different  kinds  of  moldings 
with  under-cuts. 


38  MACHINE  HOLDER  PRACTICE. 

cepting  C  on  the  molder  and  then  do  the  under-cutting  on  a 
shaper. 

In  running  the  greenhouse  sash  pattern,  Fig.  12,  in  one 
operation  thru  a  molder,  it  is  necessary  to  tilt  both  side 
heads  to  make  the  inclined  channels,  C  C.  In  case  the  in- 
side head  will  not  tilt  enough  to  make  this  cut,  and,  if  there 
is  only  a  comparatively  small  amount  to  run,  the  material 
can  be  put  thru  the  machine  twice  in  order  to  cut  both  side 
channels  with  the  tilted  outside  head.  If  the  latter  method 
is  followed,  the  top  and  outside  heads  should  be  the  only 
ones  in  action  during  the  first  run.  The  top  head  should 
carry  surfacing  knives  to  lightly  dress  the  top  surface,  thus 
making  the  stock  uniform  in  thickness  .so  that  a  pressure 
bar  can  be  used  to  hold  it  firmly  in  place  while  passing  the 
outside  head.  Knives  on  the  outside  head  should  be  set  to 
surface  the  side  and  mill  the  inclined  channel  C.  They 
will,  of  course,  remain  unchanged  during  both  runs.  On 
the  last  run  the  top  part  of  the  molding  must  be  finished 
with  the  top  head  and  the  bottom  part  with  the  bottom 
head. 

In  an  emergency,  this  particular  pattern,  Fig.  12,  can  be 
run  without  tilting  or  even  using  the  side  heads.  To  do 
this  the  stock  should  first  be  surfaced  on  one  side  and  one 
edge  and  then  run  in  a  trough  as  shown  in  Fig.  13.  Two 
runs  are  required  and  all  cutting  must  be  done  with  the 
top  head.  In  place  of  the  regular  feed  rolls,  spur  wheels 
should  be  used  and  positioned  on  the  feed  shaft  to  engage 
the  stock  just  where  the  deep  cuts  come,  i.  e.,  at  points 
B  and  C,  Fig.  13. 

There  are  many  other  kinds  of  under-cuts  such  as 
dovetailed  "ways"  in  table  slides,  dovetailed  grooves  in 
Byrkit  lath,  dovetailed  staves,  etc.,  which  can  be  run  on  a 
molder.  However,  work  of  this -kind  is  generally  turned 
out  in  large  quantities  by  factories  especially  equipped  for 
it.  Special  attachments  and  sometimes  entire  machines  of 
exclusive  design  are  built  to  manufacture  such  work. 


MAKING  UNDER-CUTS  AND  DOVETAIL  GROOVES. 


39 


There  are  table-slide  machines  which  make  such  patterns 
as  Fig.  14  and  Fig.  15,  complete  in  one  operation.  One 
particular  machine  has,  in  addition  to  the  four  ordinary 
heads,  a  pair  of  overhead  tilting  arbors  mounted  near  the 
rear  in  such  manner  that  they  can  be  fitted  with  cutters  to 
under-cut  the  corners  of  a  square-edge  groove  worked  by 
the  top  head  and  make  a  dovetailed  groove  of  it,  as  in  Fig. 
14.  Another  machine  has  overhead  vertical  spindles,  the 


Fig.  16.     Attachment   for   working   Byrkit    (dovetail)    lath,    at   rear 
end  of  an  inside  molder. 

ends  of  which  are  fitted  with  dovetailed  router  bits  to  cut 
pattern  Fig.  14,  or  the  ends  can  be  fitted  with  small  milling 
cutters  to  make  the  slot  in  pattern  Fig.  15. 

In  factories  where  production  is  sufficient  to  justify  the 
expense,  special  attachments  are  used  which  fit  on  or  in 
line  with  an  ordinary  molding  machine.  For  instance,  in 
making  Byrkit  lath  some  mills  use  a  portable  stand  fitted 
with  tilting  spindles  which  carry  either  saws  or  cutter- 


40  MACHINE  MOLDER  PRACTICE. 

heads,  and  when  the  occasion  demands  it  this  stand  is 
placed  in  line  with  the  rear  of  the  machine  to  make  the  un- 
der-cuts  after  the  straight  grooves  have  been  milled  with  the 
top  or  bottom  heads.  One  of  these  lath-making  attach- 
ments is  shown  lined  up  at  the  rear  on  an  inside  molder 
in  Fig.  16. 

An  ingenious  device  for  making  dovetailed  grooves  on 
one  edge  of  a  certain  pattern  consists  of  a  small  horizontal 
spindle  attachment  mounted  just  back  of  the  outside  head. 
The  end  of  this  spindle  carries  a  dovetail  routing  bit  so 
positioned  that  it  lines  up  exactly  with  a  square  groove 
worked  in  the  stock  with  straight  knives  on  the  outside 
head.  Therefore,  when  the  machine  is  in  operation  the 
dovetail  router  bit  finishes  the  inner  corners  of  the  groove 
cut  by  the  outside  head,  and  makes  a  perfect  dovetail 
groove.  The  spindle  attachment  has  a  pulley  which  is 
belted  to  the  machine  countershaft. 


CHAPTEE  VI. 

THE   USE   OF   SPECIAL  GUIDES  AND  FORMS. 

There  are  a  number  of  different  styles  and  kinds  of  mold- 
ing which,  to  run  thru  a  molder  successfully,  require  spe- 
cial guides  and  forms  to  hold  the  material  in  place  as  it 
passes  thru  the  machine.  One  pattern  of  molding  and  the 
forms  required  for  running  it  has  already  been  shown  in 
Fig.  13,  Chapter  Y.  Other  patterns  requiring  the  use  of 
forms  include  wood-split  pulley  bushings,  tapered  column 
staves,  piano  fall  boards,  sprung  crown  molding  for  circle 
work,  circular  church  seating,  etc.  Ordinary  small  mold- 
ings are  sometimes  run  in  a  simple  wood  form,  when  made 
on  large  machines,  because  the  form  holds  the  thin  narrow 
strips  in  place  and  prevents  them  from  buckling  and  break- 
ing while  passing  thru  the  machine. 

The  manufacture  of  wood-split  bushings  requires  absolute 
accuracy  and  for  that  reason  it  is  always  advisable  to  make 
them  in  at  least  two  operations  instead  of  one.  There  is  a 
choice  of  two  different  methods  however,  one  being  to  work 
the  stock  into  a  perfect  half-round  first  and  mill  the  chan- 
nel last,  while  the  other  is  just  the  reserve.  In  doing  the 
work  by  the  former  method,  the  stock  should  first  be  faced 
off  perfectly  flat  on  one  side  and  the  two  corners  should  be 
slabbed  off  on  a  saw  or  molder  in  order  to  lighten  the  finish 
cut.  Then  set  up  the  top  head  with  heavy  divided  knives 
as  shown  in  Fig.  17,  being  careful  that  £he  extreme  ends 
E,  E  of  the  knives  are  comparatively  wide  in  proportion  so 
there  will  be  no  possibility  of  them  chattering  or  breaking 
in  the  cut.  Fig.  17  shows  the  knives  on  only  one  side  of 
the  head,  a  quarter-round  knife  being  to  the  right  and  a 
sizing  knife  S  to  the  left.  On  the  opposite  side  of  the  head 
the  relative  position  of  the  knives  is  reversed,  therefore  it  is 
important  that  the  quarter-round  knife  on  one  side  be 


MACHINE  MOLDER  PRACTICE. 


made  to  balance  the  sizing  knife  S  on  the  other  side  and 
vice  versa.  It  may  be  necessary  to  use  a  narrow  false  guide 
of  wood  next  to  the  guide  rail  in  order  to  swing  such  wide- 
edged  knives  but  this  can  easily  be  arranged  if  conditions 
demand  it.  Should  the  knives  have  a  very  long  reach  it  is 
advisable  to  reinforce  them  with  knife  braces.  Chapter 
IX  explains  and  illustrates  the  use  of  knife  braces. 

The  half-rounds  when  finished  are  run  in  a  half-round 
form,  see  F,  Fig.  18,  in  order  to  cut  the  channel  for  the 
shafting.  The  form  F  is  iron  or  hardwood,  lubricated  on 
the  inside  with  parafine  or  grease,  and  it  extends  from  the 
in-feed  end  of  the  machine  to  a  point  some  distance  beyond 
the  top  head.  It  must  fit  the  half-round  molding  accurate- 
ly and  be  securely  bolted  to  the  bed  of  the  machine.  The 
friction  between  the  half-round  material  and  this  form  F  is 


Pig1.  17.  Knives  on  one  side  of  head  for  working-  heavy,  half- 
round  molding1.  Fig.  18.  Form  F  and  spur  wheel  A,  for  feeding 
half-rounds  to  make  pulley  bushings. 

naturally  great,  so  great  in  fact  that  smooth  feed  rolls  will 
not  feed  the  material  along.  Sharp  corrugated  rolls  or 
spur  wheels  like  A,  Fig.  18,  should  be  used  and  there  must 
be  plenty  of  weight  or  spring  pressure  employed  in  feed- 
ing. The  wood  pressure  bar  back  of  the  top  head  must  be 
adjusted  to  work  as  close  as  possible  to  the  cutting  knives 


THE  USE  OF  SPECIAL  GUIDES  AKD  FOKMS. 


and  it  must  be  set  down  fairly  tight  to  prevent  the  finished 
bushings  from  chattering  as  they  leave  the  machine.  This 
is  a  very  particular  piece  of  work  and  accuracy  is  the  thing 
to  keep  in  mind.  The  least  variation  in  the  thickness  of 


Fig.  19.     Trough  or   form,   thru  which   piano  fallboards   are   fed 
to  top  head. 

the  finished  bushings  or  their  shape  will  render  them  worth- 
less. When  running  half-round  bushings  by  the  other 
method,,  that  of  cutting  the  channel  first,  there  is  one  ad- 
vantage gained.  While  the  channel  is  being  worked  with 
the  top  head  the  outside  corners  of  the  stock  can  be  slabbed 
off  with  the  bottom  head,  thus  saving  one  operation.  On 
the  second  run,  when  the  outside  surf  ace*  is  being  worked, 
the  stock  is  run  on  top  of  a  half-round  form  or  "saddle" 
which  fits  the  channel  perfectly.  This  form  is  firmly  fast- 
ened to  the  bed  of  the  molder  and  lined  up  with  the  top 
head  knives. 

Sometimes  pulley  bushings  are  run  in  quarters.     The 
stock  is  ripped  into  squares  and  then  run  in  a  V-trough, 


44  MACHINE  HOLDER  PRACTICE. 

the  top  head  cutting  the  channel  and  square  edges,  and  the 
bottom  head  cutting  the  convex  side.  It  is  difficult  to  get 
an  absolutely  uniform  thickness  by  cutting  one  side  with 
the  top  head  and  the  other  side  with  the  bottom  head  but 
a  slight  inaccuracy  in  quartered  bushings  does  not  cause  as 
much  harm  as  in  half-round  bushings. 

Molding  the  back  and  front  fall  boards  of  pianos  is  also 
a  particular  piece  of  work  and  one  that  requires  the  use  of 


Fig.  20.     Cross-section    of    front    fallboard. 

a  trough  for  the  first  run  and  a  "saddle"  for  the  second  run. 
Fig.  19  shows  the  cross  section  of  a  back  fall  board  in  the 
proper  V-trough  for  the  first  run  thru  the  machine. 

Dotted  lines  indicate  the  manner  in  which  the  stock  is 
built  up  and  glued  before  being  worked.  The  top  head  is 
set  up  with  a  pair  of  heavy  solid  knives  to  cut  the  entire 
concave  surface.  As  a  rule  the  concave  cut  is  the  only  one 
made  during  the  first  run  because  these  boards  are  generally 
veneered  on  the  concave  surface  and  along  the  flat  surface 
A  B.  Side  A  B  is  sometimes  veneered  before  the  stock  is 
built  up.  The  concave  surface  is  veneered  immediately 
after  the  boards  are  run  thru  the  molder.  The  molded 
hinge  rabbett  M  is  worked  on  either  the  molder  or  shaper. 
After  the  fall  boards  are  veneered  bevel  B  D  is  cut  either 


THE  USE  OF  SPECIAL  GUIDES  AND  FORMS.  45 

on  a  shaper  or  on  the  molder.  When  cut  on  a  molder  the 
fall  board  is  run  on  a  saddle  or  form  having  a  convex  sur- 
face to  fit  the  concave  side.  A  pair  of  bevel  knives  are 
bolted  on  the  top  head  to  do  the  cutting. 

Fig.  20  shows  a  typical  front  fall  board  which  is  general- 
ly run  in  practically  the  same  manner  as  described  for  back 
fall  boards.  When  the  board  is  to  be  veneered  the  molded 
beads,  B,  B  are  left  off  and  a  molded  strip  is  glued  to  the 
surface  afterward.  In  case  the  front  fall  board  is  finished 
from  the  solid  wood  it  is  completely  cut  on  the  molder  in 
two  runs  with  the  exception  of  the  under  corner  C  which 
is  worked  afterward  on  a  shaper.  Corrugated  feed  rolls 
or  spur  wheels  like  A,  Fig.  18,  should  be  used  on  the  feed 
shaft  when  work  of  this  kind  is  run.  It  is  best  to  use  a 
pair  of  spur  wheels  for  the  second  run  and  position  them 
on  the  feed  shaft  so  they  straddle  the  hump  of  the  fall 
board.  The  saddles  or  forms  over  which  fall  boards  and 
such  work  are  run  are  made  of  solid  wood,  molded  accurate- 
ly to  proper  shape  and  bolted  securely  to  the  machine  bed. 
The  saddle  should  line  up  parallel  with  the  guide  rail  and 
should  extend  well  past  the  top  head  so  the  pressure  bar 
can  be  used  to  good  advantage. 

Tapered  staves  for  tapered  wood-stave  columns  are  often 
run  on  ordinary  molders,  altho  there  are  special  molders 
with  moving  side  heads  guided  by  cams  for  this  purpose, 
see  Fig.  21.  There  are  different  methods  of  running  tap- 
ered, staves  but  forms  are  required  in  every  case,  unless  a 
special  machine  or  attachment  is  employed,  and  the  forms 
must  pass  thru  the  machine  with  the  staves.  In  order  to 
keep  the  staves  moving  thru  the  machine  continuously  there 
should  be  three  sets  of  forms  so  that  while  one  form  is  in 
the  machine  the  helper  is  taking  one  out  and  passing  it 
back,  and  the  feeder  is  starting  another  into  the  machine. 

If  only  plain  bevel-edged  staves  are  required  they  can  be 
completed  in  one  operation  by  using  sets  of  forms  like  those 
shown  in  Fig.  22.  There  are  no  lugs  on  these  forms  as  the 


46 


MACHINE  HOLDER  PRACTICE. 


815? 

fi8«' 

<D  '2     -  bJO 

§|s.s 

a)  5^2 


S| 


. 

-S..-5 

•H         ^ 


THE   USE  OF  SPECIAL  GUIDES  AND  FORMS.  47 

points  of  a  few  sharp  nails  sticking  thru  them  give  suf- 
ficient grip  on  each  stave  to  prevent  any  slippage.  When 
staves  are  run  in  this  manner  the  material  should  first  be 
surfaced  to  uniform  thickness,  since  the  top  head  is  idle 
during  the  tapering  process.  Only  the  side  heads  are  used 
and  they  are  fitted  with  knives  wide  enough  to  cut  the  full 
thickness  of  a  set  of  forms  containing  a  stave. 

In  running  tapered  staves  on  which  a  tongue  and  groove 
joint,  or  any  other  style  of  joint,  with  the  exception  of  the 


END  SIDE  VIEW 


Fig.  22.     One  method  of  making-  plain  tapered  staves  in  one 
operation. 

plain  joint  mentioned,  is  required,  the  staves  are  put 
thru  the  molder  twice,  working  only  one  edge  each  time. 
Fig.  23  shows  a  simple  plan  for  laying  out'  staves  and  ob- 
taining correct  bevels.  One  must  plan  to  use  lumber  thick 
enough  for  the  work  and  always  locate  the  tongue  and 
groove  joint,  or  whatever  style  of  joint  is  used,  as  near 
as  possible  to  the  inner  side  of  the  staves  so  that  when  the 
columns  are  turned  the  turning  tool  will  not  cut  into  the 
irregular  part  of  the  joint.  The  number  of  staves  to  use 
in  a  column  will  depend  largely  upon  the  size  of  the 
columns  and  the  thickness  of  the  lumber  available.  The 
stock  for  making  staves  may  be  either  rough  or  surfaced 
and  ripped  either  straight  or  tapered,  but  it  must  be  cut  to 
an  even  length.  If  the  stock  is  surface^  to  an  absolutely 
uniform  thickness  the  top  head  need  not  be  used.  Other- 
wise it  must  be  used  on  the  first  run  to  bring  all  staves  to 
the  same  thickness.  Always  run  staves  with  the  narrow  or 
inner  side  to  the  top  and  work  the  beveled  edge  of  tapered 
staves  with  the  outside  head.  The  side  head  need  not  be 
tilted  unless  the  profile  of  the  joint  requires  it.  If  the 


MACHINE  MOLDER  PRACTICE. 


stock  for  staves  is  not  ripped  to  a  taper.,  the  staves  may  be 
run  the  first  time  without  tapered  forms.  Simply  run 
the  tongue  edge  without  taper  but  to  correct  bevel.  Then 
with  a  set  of  forms  corresponding  to  the  thickness,  length 


Fig.  23.     Showing  how  staves  for  tapered  columns  are  laid  out. 

and  taper  of  finished  staves,  see  Fig.  24,  put  the  stock 
thru  for  the  final  run,  this  time  cutting  a  groove  to  fit 
the  tongue.  During  this  final  run  the  top  head  need  not 
be  used  but  the  pressure  bar  should  be  set  down  moder- 
ately tight  to  hold  the  staves  firmly  to  the  bed  of  the  ma- 
chine as  they  pass  the  side  head.  On  the  other  hand,  if 


THE  USE  OF  SPECIAL  GUIDES  AND  FORMS.  49 

the  stave  stock  is  ripped  to  a  taper  then  tapered  forms  must 
be  used  for  both  runs.  The  forms  should  each  have  a  lug 
at  the  end,  see  L,  Fig.  24,  or  sharp  nail  points  along  the 
edge  next  to  the  stave  in  order  to  prevent  any  slippage 
while  passing  thru  the  machine.  At  the  beginning  of 
the  final  run  the  staves  should  be  tried  for  correct  bevel 
just  as  soon  as  enough  are  finished  to  make  a  column. 
Accuracy  is  very  important  in  stave  work  as  the  slightest 
deviation  in  bevel  amounts  to  considerable  when  multiplied 
by  the  number  of  staves  required  to  make  a  complete 
•  column. 

When  straight  staves  are  run  on  a  molder  both  side 
heads  and  the  top  head  are  used  and  one  run  thru  the 


MACHINE  GUIDE  RAIL 


TAPERED  FORM 


STAVE 


Fig.  24.     Stave  in  position  alongside  tapered  form. 

molder  completes  the  job.  In  this  work,  when  the  first 
good  stave  is  thru  the  machine  there  should  be  enough 
short  sections  cut  from  it  to  make  a  complete  circle  of  the 
required  column.  The  slightest  inaccuracy  can  then  be  de- 
tected and  corrected  in  time  to  avoid  any  spoiled  work. 
When  the  correct  bevel  and  joint  are  obtained  a  set  of 
short  sections  should  be  assembled  into  a  complete  circle 
and  tied  securely  with  a  string.  This  will  serve  as  con- 
vincing evidence  that  the  staves  fit  perfectly  and  it  should 
be  kept  by  the  molderman  until  after  the  staves  have  been 
glued  up. 

Sprung  crown  or  cornice  molding  for  circular  porches, 
towers,  etc.,  is  another  kind  of  work  which  at  first  sight  ap- 
pears difficult,  if  not  impossible  to  make  on  an  ordinary 
molder,  but  in  reality  it  is  very  simple  when  proper  forms 


50 


MACHINE  HOLDER  PRACTICE. 


are  used.  The  fact  that  this  kind  of  molding  sets  at  an  an- 
gle and  is  sprung  around  a  circle  makes  it  necessary  to  treat 
it  as  a  narrow  flat  strip  bent  around  a  large  cone.  There- 


Fig.  25.     Method   of  laying  out   sprung  crown   molding  for   cornice 
of  circular  porch  or  tower. 

fore,  it  must  be  sawed  to  a  certain  radius  to  make  it  line 
up  level  and  fit  properly  when  sprung  into  place  around 
the  circle.  The  method  of  finding  the  correct  radius  for 
sawing  the  stock  appears  in  Fig.  25.  The  back  of  the 


THE  USE  OF  SPECIAL  GUIDES  AND  FORMS.  51 

molding  (the  pitch  line)  is  simply  continued  until  it 
strikes  a  line  dropped  from  the  center  of  the  circle  and  the 
distance  from  this  intersection  to  the  farthest  edge  of  the 
molding  is  the  radius  which  must  be  used  in  sawing  out 
the  stock,  see  Fig.  25. 

In  Fig.  26,  A,  B  and  C,  respectively,  are  shown  three 
ways  to  run  flat  circular  work  such  as  that  just  described. 
In  each  case  the  edge  is  run  against  a  circular  form  or 
guide  of  wood  which  is  clamped  solidly  to  the  machine  bed. 
It  will  be  observed  that  in  both  illustrations,  A  and  B,  Fig. 
26,  the  inside  of  the  circle  is  run  next  to  the  form,  the  only 
difference  in  the  two  being  that  at  A  the  form  is  next  to 
the  guide  rail  while  at  B  it  is  on  the  outside.  This  dif- 
ference is  immaterial,  either  method  may  be  used  to  suit 
one's  convenience  since  the  principle  is  the  same  in  each. 
Both  methods  are  recommended  and  whenever  possible 
either  A  or  B  method  should  be  used  in  preference  to  that 
shown  at  C.  The  reason  why  A  and  B  are  preferred  is 
because  the  feed  rolls  can  be  used  to  good  advantage  in 
getting  the  material  thru  the  machine  if  the  circle  is  not 
too  small  in  radius.  The  action  of  the  rolls  at  A  and  B 
tends  to  crowd  the  material  up  tightly  to  the  form  as  it 
feeds  thru,  whereas  at  C  just  the  reverse  is  the  case. 
In  attempting  to  feed  circle  work  by  method  C  the  rolls 
carry  it  straight  forward  and  away  from  the  form.  How- 
ever, method  C  is  sometimes  the  only  alternative,  as  in  the 
case  of  very  wide  material  such  as  circular  church  seating, 
etc.  It  is  frequently  necessary  when  running  a  few  wide 
pieces  to  the  guide  as  shown  at  C,  to  raise  the  rolls  and  feed 
the  work  by  hand. 

Wlien  running  flat  circular  work  of  this  kind  the  top 
head  is  usually  the  only  one  used  altho  sometimes  one 
of  the  side  heads  can  be  brought  into  action  if  necessary. 
In  making  crown  molding  like  Fig.  25,  the  material  is  put 
thru  the  machine  twice,  the  bevels  on  the  back  being 
worked  the  first  time  and  the  face  the  last  time.  Circle 


MACHINE  HOLDER  PEACTICE. 


/  I  x 

/  TO  CENTER  OF  RADIUS         \ 

^  S  I  V  \ 


\  CORRECT  ^ 

•  V-   i  -    , 

\          TO  CENTER  OF  RADIUS          / 

/ 


\       TO  CENTER  OF  RADIUS      ' 


Fig.  26.     Arrangrement  of  guides  for  running-  circle  work. 


THE  USE  OF  SPECIAL  GUIDES  AND  FORMS. 


53 


work  can  also  be  made  on  edge,  that  is,  the  concave  or 
convex  side  or  edge  molded  with  the  top  head  by  the  use  of 
proper  forms,  see  Fig.  27.  This  class  of  work  is  really 
shaper  work  and  is  seldom  run  on  a  molder  except  in 
emergencies. 

In  a  certain  large  car  shop  the  segment  heads  for  street 
car  windows  are  run  on  a  small  sash  sticker  in  forms  as 


FORM  OR  FALSE  BED 


Fig.  27.     Molding  segment  and  circle   work  on  edge. 

shown  at  A,  Fig.  27.  The  sticker  is  used  especially  for 
this  work  and  instead  of  having  regulation  square  heads  it 
is  fitted  with  circular,  milled,  4-wing  cutters  which  retain 
their  correct  shape  until  worn  out.  These  cutters  do  not 
chip  or  tear  the  surface  of  the  stock  when  running  against 
the  grain  on  the  last  half  of  each  piece.  Both  feed  rolls 
are  arranged  to  bear  on  the  edge  of  the  stock  so  that  a  con- 
tinuous power,  feed  is  maintained. 

When  running  heavy  work  over  circular  forms  it  is  fre- 


MACHINE  MOLDER  PRACTICE. 


quently  necessary  to  remove  one  or  both  top  feed  rolls  and 
feed  the  stock  by  hand,  especially  if  the  circle  is  of  small 
radius.  One  must  always  be  guided  in  such  emergencies 
by  his  own  good  judgment  as  no  hard  and  fast  rules  are 
applicable. 


A  square,  self-centering-  side  head  fitted  with  thin  steel  knives 
which  are  clamped  in  place  with  caps  and  bolts. 


CHAPTEE  VII. 

RUNNING  MOLDING  FACE  DOWN. 

Early  types  of  molding  machines  were  designed  to  make 
molding  face  up,  evidently  because  this  seemed  to  be  the 
only  proper  way  to  run  it.  Bottom  heads,  therefore,  were 
made  smaller  than  top  heads,  and  driven  by  lighter  belts 
and  smaller  pulleys.  The  overhanging  part  of  the  machine 
bed  which  carried  the  bottom  head  was  none  too  well  sup- 
ported. In  those  days  probably  no  one  thought  of  running 
molding  upside  down,  and  if  he  had  attempted  to  do  it  with 
the  machines  then 'in  use  he  would  more  than  likely  have 
made  a  complete  failure.  The  bottom  heads  were  too  light 
and  did  not  have  sufficient  belt  power ;  there  was  not 
enough  room  to  accommodate  the  swing  of  large  knives, 
and  being  mounted  at  the  extreme  end  of  a  long  overhang- 
ing bed,  the  bottom  head  would  have  produced  wave  marks 
on  the  face  of  the  molding  if  heavy  cutting  had  been  at- 
tempted. Some  primitive  types  of  molders  are  still  in 
service,  and  needless  to  say,  it  is  out  of  the  question  to  try 
to  do  anything  but  very  light  work  with  the  bottom  heads. 

Modern  molding  machines,  however,  are  built  differ- 
ently. The  bottom  heads  are  equal  to  the  top  heads  in  size 
and  power,  and  the  space  around  them  is  adjustable  to  per- 
mit the  swing  of  reasonably  long  knives.  They  are  amply 
supported  in  a  massive  machine  frame.  Tha  bed  plate  at 
the  rear  swings  down  instead  of  sideways,  thus  giving 
convenient  access  to  the  knives.  It  is  an  easy  matter  to  run 
molding  face  down  on  the  later  machines*;  in  fact,  practical 
moldermen  have  learned  that  in  many  cases  much  better 
results  are  obtained  by  practicing  the  face-down  method. 

Numerous  arguments  abound  in  favor  of  running  ordi- 
nary molding  face  down,  but  probably  the  chief  reason  re- 
sponsible for  a  general  adoption  of  the  face-down  practice 
is  the  increased  cost  of  lumber  and  the  consequent  tendency 


56 


MACHINE  HOLDER  PRACTICE. 


of  saw  mills  to  saw  more  closely,  scanting  the  lumber  gen- 
erally instead  of  sawing  full  thickness.  Shrinkage,  due  to 
kiln-drying,  leaves  the  stock  even  thinner,  hence  when  it 
is  ready  to  be  manufactured  into  molding  a  large  percent 
of  it  is  likely  to  be  considerably  scant  of  standard  thickness. 


MACHINE  BED 

FIG.  29 


Fig.  28.  K  is  roughing  cutter  on  side  head.  W,  X,  Y,  Z  are 
combination  of  cutters  for  working-  mold  M.  B  is  wood  block 
which  supports  overhang-ing-  edge  E.  Fig.  29.  M  is  picture 
mold  being  worked  face  down.  B  is  supporting  block. 

For  example,  suppose  4/4  stock  is  to  be  used  for  molding 
which  finishes  25/32-in. ;  if  run  face  up  it  must  measure 
about  15/16-in.  in  thickness  or  rough  spots  will  appear  on 
the  face  of  the  molding;  if  run  face  down,  however,  it  can 
be  scant  %-in.  thick  and  still  make  perfect  molding.  The 
face-down  method,  therefore,  is  often  the  means  of  pre- 
venting the  loss  of  an  immense  amount  of  good  lumber 
on  account  of  the  scant  thickness. 

Another   decided   advantage   in  the   face-down  process. 


RUNNING  MOLDING  FACE  DOWN.  5? 

which  is  especially  noticeable  when  making  molding  from 
unsurfaced  lumber  is  that  the  bottom  head  almost  invari- 
ably produces  smoother  work  than  the  top  head.  This  is 
due  to  the  fact  that  the  bottom  head  always  takes  a  cut 
of  uniform  depth  regardless  of  the  varying  thickness  of  the 
rough  sawed  stock,,  and  because  it  is  far  removed  from  the 
infeed  rolls  and  top  chipbreaker.  The  bottom  head  also 
produces  more  accurate  work  as  a  rule,  because  when  the 
stock  reaches  it  the  material  is  leveled  off  and  sized  to  uni- 
form thickness  and  width,  and  closely  confined  between  side 
guides  and  under  the  pressure  bar. 

When  moldings  are  run  face  down,  practically  all  formed 
pressure  bars  are  tlispensed  with.  Only  a  few  plain  flat 
bars  of  different  widths  to  suit  the  various  widths  of  mold- 
ing are  needed.  If  a  small  chip  or  part  of  a  knot  lodges 
under  the  pressure  bar  and  scores  the  molding,  no  harm 
is  done  because  the  damage  is  on  the  back,  whereas,  if  the 
molding  is  run  face  up  the  least  scratch  on  the  top  surface 
may  ruin  it.  It  often  happens  that  several  hundred  feet 
of  molding  are  run  before  the  operator  discovers  that  the 
surface  is  being  scored  and,  of  course,  if  it  is  being  worked 
face  up  this  amount  is  spoiled. 

There  is  an  additional  convenience  in  setting  up  a  bottom 
head  for  new  molding  and  checking  the  correctness  of  the 
set-up  because,  when  the  pressure  bar  is  set  down  properly, 
one  can  feed  the  first  piece  a  few  inches  over  the  bottom 
head  and  quickly  determine  its  degree  of  correctness  with- 
out removing  it  from  the  machine.  If  edge-cutters  or  split- 
ters, which  cut  entirely  through  the  molding  are  employed, 
they  can  be  used  to  greater  advantage  on  the  bottom  head 
than  on  the  top  head  because  there  is  no  danger  of  cutting 
into  iron  if  they  are  set  out  a  fraction  of  an  inch  too  far. 

Here  is  one  more  point  worthy  of  mention.  When  feed- 
ing anything  but  the  very  smallest  moldings,  if  the  last 
end  of  a  piece  passes  the  infeed  rolls  without  another 
closely  butted  against  it,  an  ugly  mark  is  usually  made 


58  MACHINE  MOLDER  PRACTICE. 

across  its  top  surface  by  the  top  head.  This  end  is  there- 
fore spoiled  if  the  face  side  of  the  molding  is  at  the  top, 
but  if  it  is  on  the  bottom,,  no  damage  is  done. 

In  Fig.  28  there  is  illustrated  another  advantage  in  the 
face-down  method  which  may  be  taken  into  account  when 
any  molding  requires  extra  heavy  cuts  along  one  or  both 
face  corners.  These  cuts  are  often  difficult  and  dangerous 
to  make  with  single  knives  on  one  head,  but  by  running  the 
material  face  down,  the  heavy  cuts  can  be  divided  between 
knives  on  the  side  and  bottom  head.  For  instance,  in  Fig. 
28,  a  plain  bevel  knife  K  on  the  side  head  cuts  away  more 
than  half  of  the  surplus  wood  and  leaves  only  a  compara- 
tively light  cut  for  the  finishing  knives  W,  X,  Y,  Z  on  the 
bottom  head.  This  is  a  more  safe  and  easy  way  to  run 
large  moldings  of  this  type  and  it  is  a  method  which  in- 
variably produces  a  smoother-finished  product.  There  is  so 
much  of  the  under  side  of  this  molding  cut  away,  however, 
that  only  a  very  narrow  part  N  rests  on  the  bed  as  it  leaves 
the  bottom  head.  Therefore,  the  last  end  of  each  piece  is 
likely  to  "cave  into  the  knives"  as  the  cut  is  completed.  This 
is  prevented  by  a  block  B  which  acts  as  a  support  for  the 
overhanging  edge  E.  In  fact,  suitable  blocking  should 
always  be  used,  as  illustrated  at  B,  Fig.  28,  and  B,  Fig.  29, 
to  aid  in  supporting  moldings  which  are  under-cut  to  such 
an  extent  that  they  are  apt  to  "cave  in"  or  "roll"  as  they 
leave  the  bottom  head.  The  adjusting  of  what  blocking  is 
required  does  not  consume  much  time — not  nearly  so  much 
as  would  otherwise  be  taken  up  in  making,  keeping  in  order 
and  adjusting  formed  pressure  bars  for  top-head  work.  The 
blocks  are  short  and  easily  attached  temporarily  to  the  rear 
bed  or  side  guides  by  wood  screws. 

There  are,  of  course,  some  moldings  which  cannot  be  run 
face  down  and  others  which,  altho  they  can  be  run  face 
down,  work  to  better  advantage  face  up.  In  doubtful  cases 
one  must  use  his  best  judgment  in  choosing  the  safest,  easi- 
est and  most  practical  method. 


CHAPTER  VIII. 

SPECIAL  SURFACING  AND  MILLING  KNIVES. 

When  comparatively  straight-grained  lumber  is  manufac- 
tured into  moldings,  special  knives  and  other  devices  are 
not  required.  But  in  working  curly  or  cross-grained  stock, 
or  in  making  a  groove  or  rabbett  without  planing  off  the 
flat  surfaces  adjoining  it,  there  is  need  for  something  more 
than  regular  cutters  and  ordinary  methods  of  knife  setting 
to  produce  smooth  ^ork. 

One  of  the  most  general  methods  employed  to  obtain  a 
smooth  finish  when  working  curly  or  cross-grained  wood  is 
to  back  bevel  the  knives  as  shown  at  B,  Fig.  30.  A  knife 
ground  in  this  manner  makes  a  scraping,  non-tearing  cut 
instead  of  "picking  up"  and  tearing  out  the  grain.  More 
power  is  required,  however,  to  drive  it  thru  the  wood 
and  the  method  can  only  be  used  successfully  on  thoroly 
kiln-dried  lumber.  Equally  as  good  results  can  be  obtained 
by  reversing  the  knives  on  the  head  (the  knives  being 
turned  upside  down)  but  this  is  only  recommeded  in  emerg- 
encies and  on  short  runs  because  knives  running  in  this 
manner  are  necessarily  limited  to  light  cuts  on  account  of 
the  added  power  required  to  drive  them  thru  the  stock. 

Another  method  of  preventing  torn  grain  in  flat  work  is 
to  set  ordinary  knives  so  they  have  about  half  the  usual  pro- 
jection past  the  lip  of  the  head,  say  a  scant  1/16-in.  if  that 
is  sufficient  to  give  clearance  for  the  bait  heads.  Should 
there  be  insufficient  clearance  when  the  knives  are  set  so 
close,  or,  if  the  lip  of  the  head  is  nicked  and  in  bad  con- 
dition, the  same  effect  can  be  obtained  by  placing  a  piece  of 
thin,  flat  steel  (part  of  a  resaw  blade  will  do)  under  the 
knives  as  shown  at  C,  Fig.  30.  The  piece  of  steel  must 
be  slotted  like  the  knife  and  its  working  edge  ground  per- 
fectly straight.  This  edge  is  set  back  only  3/64-in.  or 


MACHINE  MOLDER  PRACTICE. 


cuta  the  face  of  the  rabbett,  see  S  to  T,  Fig.  33,  and  a  spe- 
cial knife  like  Fig.  34  or  35  cuts  the  edge  of  the  rabbett 
as  E  to  S,  Fig.  33.  The  knife  shown  in  Fig.  34  is  really 
an  ordinary  beveled  knife  turned  upside  down  on  the  head 


FIG.  33 


FIG.  32 


Figs.  32  and   33.     Methods   of  fitting  up   rabbetting  knives   to 
make  non-tearing  cut. 

but  the  side  clearance  is  reversed.  Use  is  made  of  a  side 
spur,  S  A,  and  only  a  very  slight  side  clearance  C,  just 
enough  to  prevent  the  back  of  the  knife  from  striking  the 
edge  of  the  rabbett.  The  knife  is  set  so  spur,  S  A,  cuts  pre- 
cisely the  depth  of  the  rabbett.  One  might  think  that  the 
point  S  of  the  spur  does  the  entire  edge  cutting  but  this  is 
not  the  case.  The  cutting  edge  extends  from  point  S  to 
point  A,  Fig.  34,  and  it  produces  a  non-tearing,  slicing  cut. 
The  knife  shown  in  Fig.  35,  with  its  knife-like  curved  edge, 
is  forged  to  shape  and  ground  to  make  a  slicing  cut  similar 
to  that  just  described.  It  is  shown  in  the  form  of  a  spike 
bit,  but  can  be  made  slotted  if  desired.  Great  care  is  re- 
quired in  setting  either  of  these  special  edge-cutting  knives, 
but  once  a  knife  of  either  type  is  properly  sharpened  and  set, 
it  will  cut  a  perfectly  smooth  square  edge  without  tearing, 
regardless  of  the  grain  or  kind  of  wood  being  worked. 

Knives  for  cutting  grooves  should  be  made  and  used  in 
pairs  of  rights  and  lefts,  that  is,  one  to  cut  one  side  of  the 


SPECIAL    SURFACING   AND   MILLING   KNIVES. 


63 


groove  and  its  mate  to  cut  the  other  side,,  so  that  as  the  side 
edges  of  the  knives  wear  away  by  repeated  sharpening  they 
can  still  be  set  out  to  cut  the  standard  width  grooves  for 
which  they  are  intended.  Instead  of  using  grooving  knives 
with  side  spurs,  as  shown  in  Fig.  33,  one  can,  if  he  prefers, 
obtain  equally  as  good  results  with  knives  which  have  a 
shear-cutting  bevel  on  the  front.  The  knives  are  paired 
and  positioned  on  the  head  so  the  sharp,  shear-cutting  edge 
is  turned  to  the  outside  to  make  the  edge  cut. 

In  Fig.  36  is  shown  an  excellent  cutter  for  milling  nar- 
row grooves.     There  should  be  a  pair  of  these  cutters,  and 


FIG.  35 


Figs.   34   and 


Special  knives  for  cutting  the   edge   of  rabbetts. 


the  saw  teeth  instead  of  being  filed  square  across  at  the 
front  should  be  given  a  slight  lead  or  bevel  toward  the 
outer  edge,  which  is  to  the  left  for  one  cutter  and  to  the 
right  for  the  other.  This  produces  a  double  shear  cut.  The 
front  teeth  of  each  cutter  are  lower  than  the  back  teeth  so 
that  they  will  not  do  most  of  the  cutting  when  a  fast  rate 
of  feed  is  carried.  Cutters  of  this  type  stay  sharp  a  long 


64  MACHINE  MOLDER  PRACTICE. 

time  and  cut  a  remarkably  smooth  clean  groove  in  any  kind 
of  wood  at  fast  feed.  They  will  even  produce  a  smooth 
groove  on  surfaced  stock  without  the  usual  "skinning  ofP 
of  the  face  side.  In  fact,  the  first  cutters  of  this  type  ever 
made  were  designed  to  meet  just  such  an  emergency.  The 
cutters  are  made  of  ordinary  slotted  steel  blanks  which  are 
first  cut  at  A,  Fig.  36,  then  heated  a  cherry  fed  and  bent 


Fig.   36.     Special  grooving  cutter. 

as  shown.  The  bent  upright  part  of  the  cutter  is  scribed 
and  roughly  ground  to  the  cutting  circle  of  the  head,  after 
which  the  teeth  are  formed,  jointed  and  sharpened. 

Grooves  and  rabbetts  are  often  cut  with  thick  saws,  built- 
up  thin  saws,  wabble  saws,  Shinier  heads,  and  various  high- 
speed cutterheads  mounted  on  the  proper  spindles  of  the 
molder,  and  while  these  are  all  excellent  methods  they  are 
in  most  instances  only  profitable  on  long  runs  of  standard 
patterns.  In  many  cases  some  of  these  latter  methods  can 
be  used  with  good  results  for  making  various  irregular- 
shaped  moldings  when  unusually  cross  or  curly-grained 
stock  is  encountered. 


CHAPTEK  IX. 

BRACES  AND  KNIVES  FOR  HEAVY  WORK. 

When  making  large  moldings  which  require  deep  heavy 
cuts  with  long  knives,  the  need  of  braces  or  reinforcing  de- 
vices, and  sometimes  special  knives,  immediately  becomes 
apparent.  The  use  of  extra  large  knives  is  dreaded  by  some 
moldermen  because  of  the  possible  danger  involved,  but  if 
the  knives  are  properly  made,  accurately  balanced,  bolted 
and  braced  in  a  substantial  manner,  there  is  scarcely  any 
danger  of  having  a  "smash  up."  By  properly  made,  it  is 
meant  that  they  should  be  made  of  good  steel,  somewhat 
thicker  than  the  ordinary  knife  steel,  and  that  the  cutting 
edges  should  only  be  hardened  a  short  distance  back,  thus 
leaving  the  main  body  of  the  knife  tough  rather  than  hard 
and  brittle.  A  very  hard  knife  is  almost  sure  to  break  in  a 
deep  or  heavy  cut  no  matter  how  well  it  is  braced. 

In  designing  or  selecting  a  knife  brace  one  must  always 
bear  in  mind  that  the  chief  object  of  bracing  is  to  prevent 
the  overhanging  end  of  the  knife  from  bending  back  or 
shearing  its  bolts.  Another  thing  to  consider  when  select- 
ing braces  and  planning  a  set-up  for  heavy  work  is  the 
amount  of  molding  to  be  run,  whether  it  is  a  standard  pat- 
tern or  just  a  special  job  which  may  never  be  called  for 
again.  It  is  neither  wise  nor  profitable  to  spend  a  great 
deal  of  time  fitting  up  something  elaborate  for  one  small 
job,  and  it  is  equally  unwise  and  often  dangerous  to  fit  up 
a  temporary  makeshift  for  running  stock. patterns  which 
are  repeatedly  ordered  in  comparatively  large  quantities. 
Practically  every  job  of  heavy  molding  presents  problems 
peculiar  to  itself,  but  with  the  assistance  of  the  following 
illustrations  of  devices  and  descriptions  of  their  uses,  any 
molderman  should  be  able  to  quickly  solve  the  difficulties 
that  may  arise  and  turn  out  the  most  complex  kinds  of 
molding  with  ease  and  safety. 


66 


MACHINE  HOLDER  PRACTICE. 


Often  times  the  only  kind  of  reinforcement  a  knife  re- 
quires is  an  additional  bolt  at  each  side.  For  example, 
if  a  single  slotted  knife,  say  3-in.  or  more  in  width,  is  set  to 
take  a  medium  heavy  cut  the  strain  of  cutting  is  likely  to 
be  more  than  one  bolt  can  hold,  but,  if  a  bolt  is  added  to 
each  side  as  shown  at  A,  Fig.  37,  thus  making  three  in  all, 
the  knife  can  be  safely  held  in  place.  The  holding  power 


O 


O 


O 


Fig.   37.     Reinforcing  a  wide  knife  with   bolt  at  each   side. 

of  the  side  bolts  S,  S,  Fig.  37,  can  be  further  strengthened 
if  a  very  short  slot  is  made  in  each  side  of  the  knife  to  re- 
ceive about  half  or  three-quarters  of  each  bolt.  Another 
good  practice  is  to  remove  the  bolt  washers  and  substitute 
in  their  stead  a  soft  steel  plate  as  pictured  at  B,  Fig.  37. 
This  plate  is  drilled  to  receive  the  three  bolts  and  when  in 
position  it  spans  the  entire  knife,  thereby  serving  the  dual 
purpose  of  clamping  cap  and  bolt  washer. 

Long,  overhanging  knives  require  bracing  at  points  be- 
yond the  lip  of  the  head  and  reasonably  close  to  their  cut- 


BRACES  AND  KNIVES  FOR  HEAVY  WORK. 


67 


ting  edges.  Some  very  effective  braces  for  long  knives  are 
shown  at  C,  D,  E  and  F,  Fig.  38,  and  at  G  and  H,  Fig.  39. 
The  braces  C,  D,  E  and  F,  are  simply  different  types  of  side 
braces,  all  being  made  of  steel.  Each  brace  has  a  mate 
to  balance  it.  It  is  also  a  good  plan  to  have  right  and  left 


Fig. 38.     Four  different  kinds  of  side  braces. 

side  braces  so  that  knives  can  be  braced* on  both  sides  if 
necessary.  The  brace  C  is  made  of  ordinary  slotted  steel 
and  arranged  to  hook  over  the  lip  of  the  head  and  rest  in 
position  alongside  the  knife  it  reinforces.  Braces  D  and 
E  are  also  designed  to  hook  over  the  side  of  a  knife.  They 
are  bolted  to  the  side  of  the  head  immediately  in  front  of 
the  knife  which  they  brace.  The  brace  F  is  similar  to  D 
and  E  except  that  it  is  bent  around  at  one  end  to  fit  into 


68 


MACHINE  HOLDER  PRACTICE. 


the  bolt  slot  as  shown  and  therefore  does  not  require  any 
bolts.  The  three  braces  D,  E  and  F,  are  each  offset,  as 
illustrated,  to  clear  the  lip  of  the  head  and  bring  the 
"anchor  point"  near  the  cutting  edge  of  the  knife. 

When  the  shape  of  a  long  knife  is  such  that  it  cannot  be 
braced  along  the  sides  with  braces  as  shown  in  Fig.  38,  an 


Fig.  39.     Two  ways  to  brace  extra  long  knives. 

effective  method  of  anchoring  it  is  to  drill  a  hole  near  the 
middle  of  the  projecting  part  and  insert  a  long  bent  bolt 
as  indicated  at  G,  Fig.  39,  or  an  eye  bolt  as  shown  at  H, 
Fig.  39.  The  type  of  anchor  bolt  chosen  should  always  be 
used  with  a  mate  of  the  same  kind,  size  and  weight  in  order 
to  make  a  good  running  balance  when  the  machine  is  set 
up. 

As  a  further  safety  precaution  it  is  well  to  have  closed 


BRACES  AND  KNIVES  FOR  HEAVY  WORK. 


69 


slots  in  all  extra  long  knives,  see  K,  Fig.  39.  A  knife  with 
a  closed  slot  has  greater  strength  at  the  back  where  it  is 
bolted  to  the  head.  It  cannot  spread  at  the  slot  nor  get 
away  during  service  without  stripping  its  bolts.  These 
extra  long  knives  should  also  be  bent  slightly  forward,  as 


Fig.  40.     Four  types  of  "scoop"  or  "loop"  knives  for  making1  gutter. 

shown  at  K,  to  give  the  cutting  edge  a  more  acute  cutting 
angle  because,  when  bent  forward,  they  cut  more  easily,  re- 
quire less  power,  and  consequently  cause  less  strain  on  the 
bolts  and  braces. 

While  the  type  of  knife  illustrated  at  K,  Fig.  39,  will 
serve  fairly  well  for  making  deep  cuts,  the  so-called  scoop 
or  loop  knives  (four  different  kinds  of  which  are  pictured 
in  Fig.  40)  are  far  superior  in  every  way.  The  cutting 
edges  of  knives  A,  B,  C  and  D,  Fig.  40,  are  the  same  but  the 
manner  in  which  the  different  types  of  knives  are  bolted 
to  the  head  differs.  These  knives  are  made  of  good  bar 
steel  and  their  cutting  parts  are  bent  to  make  the  shape 
desired.  Proper  allowance  is  naturally  made  for  clearance 
in  each  case.  Knives  of  this  kind  will  cut  thru  solid 
wood  with  remarkable  ease  and  produce  real  smooth  work. 
The  shavings  and  air  pass  right  thru  the  loop  of  the 
knives,  hence  there  is  much  less  resistance  offered  to  their 


70 


MACHINE  HOLDER  PRACTICE. 


motion  and  less  power  is  required  to  drive  them.     This 
means  an  added  element  of  safety  which  is  important. 

The  knife  A,  Fig.  40,  has  two  cutting*  edges  and  is  de- 
signed to  slip  onto  a  cutterhead  spindle.  A  pair  of  the 
knives  should  be  used,  one  with  the  ends  bent  to  the  right, 


b 

B 

Fig.  41.     Bracing  a  loop  knife  with  T-bolt  and  steel  block  B. 

the  other  with  ends  bent  to  the  left,  and  the  cutters  should 
be  separated  by  spacing-collars  and  clamped  in  position 
on  a  spindle  in  the  same  manner  that  a  saw  is  fastened  to 
its  arbor.  One  -thing  is  certain  about  knives  of  this  type, 
they  cannot  get  away  after  being  properly  clamped  onto  a 
spindle.  This  is  a  point  in  their  favor  but,  on  the  other 
hand,  when  they  are  used  no  other  knife  can  be  positioned 
with  them  on  account  of  the  absence  of  a  cutterhead. 

Knives  B,  C  and  D,,  are  made  in  pairs  and  designed  to 
bolt  directly  onto  any  ordinary  square-slotted  head.    Knife 


BRACES  AND  KNIVES  FOR  HEAVY  WORK. 


71 


C  is  made  of  bar  steel  which  is  thicker  but  narrower  than 
the  steel  used  for  making  types  A,,  B  and  D.  The  cutting 
part  is  heated  and  hammered  thinner  and.  wider  when  the 


Fig.  42.     Another  method  of  clamping-  loop  knives  to  a  square 
cutterhead. 

knife  is  made.  Knife  C  possesses  a  marked  advantage  over 
the  other  three  types  of  scoop  knives  because  it  is  adjust- 
able for  depth  of  cut.  Fig.  41  shows  one  method  of  bolting 
and  bracing  a  knife  like  C,  Fig.  40,  but  a  better  method 
appears  illustrated  in  Fig.  42.  Usually  the  lips  on  two 
corners  of  the  head  are  filed  down  level  with  the  sides  of 


MACHINE  HOLDER  PRACTICE. 


the  head  to  accommodate  a  pair  of  knives  that  are  put  on 
in  this  way,  but  it  is  not  absolutely  necessary  to  do  this 
since  the  two  sides  of  the  head  can  be  blocked  up  with  plates, 
as  shown,  to  make  them  come  level  with  the  edges  of  the 
lips.  This  method  of  positioning  the  knives  gives  them 


Fig.  43.     G  is  a  pattern  of  ogee  gutter.     M  is  loop  knife  for 
cutting  the  ogee. 

solid  backing  all  along  the  back  and  up  to  their  cutting 
edge  without  extra  bracing.  A  single  powerful  bolt  and 
square  cap  which  fits  over  the  knife,  as  illustrated,  are 
usually  all  that  are  needed  to  hold  each  knife  on  the  head. 
This  method  of  putting  knives  on  a  square  head  gives  the 
bolts  greater  leverage,  and  as  a  result  the  knives  are  easier 
to  hold  and  the  element  of  danger  greatly  reduced. 

Knife  D,  Fig.  40,  is  designed  to  straddle  the  corner  of  a 
square  head  and  is  bolted  on  both  sides,  therefore,  it  requires 
no  extra  bracing.  In  making  any  of  the  knives  shown  in 
Fig.  40,  good  steel  of  generous  thickness  should  be  used  in 
order  to  offset  any  danger  of  the  knives  collapsing  while  in 
service.  The  steel  for  knives  A,  B  and  D,  should  be  3/8-in. 
or  7/16-in.  thick  while  that  for  knife  C  should  be  about 
9/16-in.  or  5/8-in,  in  thickness  if  the  knives  are  intended 
for  making  cuts  2-in.  or  more  in  depth.  Knives  of  the  type 
just  described  are  used  quite  extensively  in  Pacific  Coast 


BRACES  AND  KNIVES  FOR  HEAVY  WORK.  73 

mills  for  cutting  different  patterns  of  heavy  solid  wood 
gutter,  one  form  of  which  is  shown  at  G,  Fig.  43.  They  are 
also  used  for  various  other  kinds  of  heavy  cutting. 

Eeally  the  best  way  to  make  plain  deep  cuts  such  as 
gutter,  trunking  channels,  deep  grooves,  rabbetts,  etc.,  is 
to  use  sectional  slip-on  cutterheads.  When  this  equipment 
is  available  an  enlarged  section  or  disc  of  the  required 
width  is  positioned  in  line  with  the  deep  cut,  and  the  re- 
maining part  of  the  molder  spindle  simply  carries  sections 
of  normal  size  cutterheads,  either  square  or  round.  This 
permits  the  use  of  ordinary  small  knives  set  at  a  normal 
projection,  therefore*  braces  are  unnecessary  and  virtually 
all  danger  is  eliminated. 

A  somewhat  crude  modification  of  this  idea  consists  of 
using  steel  blocks  which  are  bolted  to  the  sides  or  fitted  over 


Fig.  44.     Two  kinds  of  blocks  for  enlarging  square  cutterheads. 

the  corners  of  ordinary  square  slotted  heads..  Two  such 
blocks  are  shown  at  A  and  B,  Fig.  44.  It  will  be  noticed 
that  block  A  is  designed  to  be  bolted  to  the  flat  side  of  a 
square  head  while  block  B  is  made  to  fit  over  the  corner 
of  a  square  head.  Both  blocks  contain  bolt  holes  running 
thru  the  projecting  parts  which  fit  into  the  head  slots. 
The  blocks  also  contain  holes  X,  X,  which  are  tapped  for 
planer  bolts  to  hold  the  knives.  Ordinary  knives  bolted  to 


MACHINE  HOLDER  PRACTICE. 


these  blocks  require  only  a  normal  projection  to  make  very 
deep  cuts. 

Sometimes  it  is  necessary,  or  at  least  desirable,  to  run 
material  that  finishes  an  inch  or  two  wider  than  the  rated 
capacity  of  the  molder.  For  instance,  there  may  be  an 
order  for  10-in.  base  and  the  only  machine  available  is  an 
8-in.  molder.  This  means  that  the  surfacing  knives  must 
extend  out  over  the  end  of  the  head  1%  to  2-in.  Fig.  45 


Fig.  45.     Showing1  hooks  in  position  for  holding  ends  of  project- 
ing1 surfacer  knives. 

shows  how  the  overhanging  ends  may  be  supported  or  braced 
with  a  pair  of  iron  or  soft  steel  hooks.  This  is  a  make- 
shift method  but  it  will  serve  the  purpose  very  well  in 
emergencies  provided  a  comparatively  light  cut  is  taken  at 
a  moderate  rate  of  speed.  If  the  outside  head  does  not  pull 
out  far  enough  to  clear  the  work  it  can  be  fitted  with  a  spe- 
cial small  head  or  pair  of  shaper  collars  and  shaper  knives 
to  make  the  edge  cut.  Otherwise  the  side  head  can  be  re- 
moved from  the  spindle  and  the  outside  edge  of  the  wide 
molding  finished  afterward  on  a  jointer  or  shaper. 


CHAPTER  X. 

MAKING  MOLDINGS  IN  MULTIPLES. 

In  manufacturing  large  quantities  of  narrow  moldings, 
the  cost  of  production  can  often  be  materially  reduced  by 
working  the  moldings  in  multiples  or  gangs  of  two,  three, 
or  more  at  a  time  instead  of  ripping  stock  into  narrow 
strips  and  running  them  singly.  Of  course,  there  should  be 
enough  molding  of  a  kind  to  justify  the  extra  time  and  ex- 
pense incident  to  making  the  more  complicated  set-up. 
Usually  it  is  not  advisable  to  run  anything  except  stock  pat- 
terns in  multiples  and  even  they  should  not  be  run  in  gangs 
from  good  wide  lumber  if  there  is  plenty  of  narrow  ma- 
terial on  hand  for  making  them  singly.  The  extra  cost  of 
wide  lumber  must  always  be  taken  into  consideration  when 
planning  on  converting  it  into  narrow  moldings.  There  is 
certainly  no  satisfaction  in  making  an  imposing  display 
of  higher  molder  efficiency  by  running  molding  in  gangs 
if,  after  the  job  is  completed  and  properly  figured,  it  is 
found  that  the  finished  moldings  are  worth  less  than  the 
market  price  of  the  wide  lumber  from  which  they  were 
made. 

Manufacturers  of  wholesale  softwood  molding,  picture 
frame  and  embossed  molding,  run  most  of  their  narrow 
patterns  in  multiples  of  two  or  more.  There  is  this  differ- 
ence in  the  established  methods  of  making  the  different 
classes  of  moldings.  In  planing  mills  where  large  quantities 
of  woodwork  for  building  purposes  are  manufactured,  mul- 
tiple work  is  generally  run  face  down,  while  in  furniture 
and  picture  frame  factories  almost  everything  is  made  face 
up.  Any  ordinary  pattern  of  molding  can  usually  be  run 
successfully  either  way  altho  there  are  some  practical 
advantages  in  the  face-down  system  under  certain  condi- 
tions, as  mentioned  in  Chapter  VII.  The  best  way  to  run 


76 


MACHINE  HOLDER  PRACTICE. 


any  multiple  molding  depends  largely  upon  the  profile  of 
the  molding  and  the  manner  in  which  it  is  most  practical  to 
separate  the  multiples.  For  instance,,  if  the  back  of  the 
molding  is  flat,  it  can  be  run  face  down  very  satisfactory 


Fig.  46.     Examples  of  moldings  made  in  pa^rs,   face  down. 

by  surfacing  the  back  with  the  top  head,,  the  square  edges 
with  the  side  heads,  and  finally  molding  and  splitting  it, 
as  required,  with  the  bottom  head,  see  examples  in  Fig.  46. 
When  this  method  is  followed  no  wide  stock  is  separated 
into  narrow  pieces  by  the  top  head,  hence  there  are  no 
narrow  strips  to  twist,  break,  buckle  nor  get  out  of  line 
in  the  machine.  Here  is  another  point,  when  the  knives 
which  separate  the  moldings  are  on  the  bottom  head,  they 


MAKING  MOLDINGS  IK  MULTIPLES.  77 

do  not  require  such  fine  depth  adjustment  as  when  they  are 
positioned  on  the  top  head.  If  the  knives  which  divide 
the  moldings  cut  1/16-in.  or  %-in.  deeper  than  necessary, 
it  is  all  right;  the  points  simply  cut  a  little  groove  in  the 
underside  of  the  wood  pressure  bar  and  no  harm  is  done. 
On  the  other  hand,  this  extra  length  is  never  permissible 
on  the  top  head  unless  the  bed  plate  directly  under  the  head 
is  recessed  especially  to  accommodate  the  swing  of  long 
knife  points. 

In  Fig.  46,  five  different  moldings  are  illustrated  in  the 
relative  position  in  which  they  leave  a  molder  when  made 


Fig.  47.     Splitter  or  center  guide  in  rear  end  of  pressure  bar. 

in  twos.  They  are  run  in  pairs  of  rights  and  lefts  as  a 
matter  of  convenience.  Patterns  A,  B,  and  C  are  separ- 
ated by  the  points  of  double-edged  molding  knives  which 
cut  thru  the  wood  at  the  dividing  line.  In  order  to  separ- 
ate patterns  like  D  and  E,  a  narrow  straight  knife  or  some 
kind  of  splitting  cutter  must  be  used  to  cut  thru  the  square 
inside  edges.  For  the  purpose  of  holding  the  multiples 
apart  as  they  leave  the  bottom  head,  after  being  separated, 
a  splitter  is  fastened  in  the  pressure  bar  at  a  point  just 
back  of  where  the  knives  strike,  see  Fig.  47.  This  splitter 
serves  as  a  sort  of  center  guide  and  prevents  the  moldings 
from  shifting  or  playing  sidewise,  and  thus  becoming 
marred  at  the  ends  by  the  bottom  head  knives.  It  is  not 
always  necessary  to  use  a  splitter  in  the  pressure  bar  to 


78 


MACHINE  HOLDER  PRACTICE. 


separate  multiples  but  in  the  majority  of  cases  it  is  very 
advantageous.  The  question  of  when  and  where  to  use  a 
splitter,  if  at  all,  is  another  one  of  those  things  which  the 
molderman  must  decide  by  the  exercise  of  good  judgment 
based  upon  practical  experience. 

Where  the  profile  of  the  molding  is  such  that  there  is  an 
overhanging,  unsupported  edge  left  when  the  bottom  head 
knives  complete  their  cutting,  wood  blocking  must  be  fast- 


Fig.  48.     Picture  frame  moldings  made  in  pairs,  face  up. 

ened  to  the  rear  table,  see  illustration  B,  Fig.  46,  to  pre- 
vent the  last  ends  from  caving  into  the  knives  as  the  mold- 
ing leaves  the  machine.  See  other  examples  in  Chapter 
VII. 

Eeferring  to  Fig.  48,  two  patterns  of  picture  frame  mold- 
ing are  shown  at  F  and  G  as  they  appear  leaving  the  ma- 
chine when  run  face  up.  A  great  many  picture  frame 
moldings  are  run  in  twos  in  a  manner  similar  to  that  illus- 
trated at  F,  Fig.  48.  The  top  profile  and  the  dividing  kerf 
K  are  cut  by  knives  on  the  top  head  while  the  rabbett  E 
is  made  by  knives  on  the  bottom  head.  The  moldings  are 
not  separated  therefore  until  the  rabbett  E  is  cut  with  the 


MAKING  MOLDINGS  IN  MULTIPLES.  79 

bottom  head.  Frequently  this  rabbett  is  not  made  on  the 
molder  at  all  because  it  is  not  desired  to  separate  the  mold- 
ings until  after  they  have  been  passed  thru  an  embossing 
machine  and  perhaps  a  molding  sander.  The  rabbett  is 
finally  cut  and  the  moldings  separated  by  passing  the  double 
molding  thru  a  machine  fitted  with  solid  rubber  feed  rolls 
and  special  saws  or  cutters  for  milling  a  wide  central  groove 
which,  when  completed,  leaves  an  edge  rabbett  E  on  each 
piece  of  molding. 

SPLITTING  CUTTERS. 

Among  the  many  splitting  cutters  which  have  been  de- 
vised from  time  to  time  by  moldermen  and  tool  makers  all 
over*  the  country,  the  few  which  are  standing  up  best  and 
proving  most  practical  in  all  respects  are  illustrated  in  Figs. 
49  and  50.  Eeferring  to  Fig.  49,  cutters  A  and  C  are  de- 
signed to  be  fastened  with  machine  screws  on  the  side  of 
a  block  like  B,  which  is  bolted  in  the  slot  of  a  square  cutter- 
head.  Cutter  A  is  part  of  a  saw  blade  and  its  teeth  should 
be  swaged  for  best  results.  Cutter  C  is  high-speed  steel 
ground  thin  at  the  back  and  near  the  bottom  for  clearance, 
and  is  beveled  45  degrees  on  the  front  or  cutting  edge. 
Its  mate,  which  belongs  on  the  opposite  side  of  the 
head  is  beveled  in  the  opposite  direction  to  equalize  or  bal- 
ance the  cut.  Block  B,  fitting  in  the  slot  of  a  square  head 
as  it  does,  serves  to  hold  its  cutter  perfectly  in  line.  The 
cutter  D  is  made  from  a  section  of  saw  blade  and  ar- 
ranged to  fit  into  a  narrow  slot  in  a  steel  knife  blank  E, 
which  serves  as  its  holder.  The  cutter  is  secured  rigidly  in 
place  by  a  machine  screw  as  shown.  The  cutter  at  F,  Fig. 
49,  is  made  from  a  single  piece  of  steel  %-in.  or  5/16-in. 
thick.  The  steel  is  hammered  thin,  while  red  hot,  and 
bent  and  shaped  so  the  front  or  cutting  edge  is  thicker  than 
the  back  to  give  clearance.  The  front  concave  cutting  edge 
is  ground  hollow  with  a  thin  emery  wheel  so  that  both 
edges  are  cutting  edges  instead  of  only  one  as  at  C,  Fig.  49. 


MACHINE  MOLDER  PRACTICE. 


In  Fig.  50,  there  appears'  a  splitting  cutter,  a  little  more 
elaborate  in  design  than  those  just  described.  The  holder 
is  made  of  soft  steel  and  is  in  two  parts,  G  and  J,  which 
are  hinged  at  the  back  to  permit  opening  the  holder  and  in- 
serting a  high-speed  steel  cutter  H.  This  holder  folds  up 


Fig-.  49.     Four   types   of   practical   splitting   cutters. 

over  the  cutter  in  a  very  compact  manner  and  does  not  take 
any  more  room  on  the  head  than  an  ordinary  narrow  slotted 
knife.  The  whole  device  can  be  attached  to  any  square 
head  with  a  knife  bolt.  The  cutter  in  this  device,  like 
those  illustrated  at  A,  C,  and  D,  Fig.  49,  is  removable  and 
renewable. 

There  is  quite  a  variety  of  uses  which  splitting  cutters 


MAKING  MOLDINGS  IN  MULTIPLES. 


81 


can  be  put  to  in  molder  work.  They  serve  not  only  as 
splitting  cutters  for  ripping  square-edge  stock  and  separ- 
ating multiple  moldings  but  are  also  used  for  creasing  or 
kerf  ing  the  backs  of  thick  jambs,  etc.,  and  for  cutting  the 
square  edges  of  deep  rabbetts  and  grooves.  The  chief  re- 


Fig.  50.     Special  high-speed  steel  splitting  cutter  and  Us  holder. 

quirements  of  a  successful  splitting  cutter  are  plenty  of 
back  strength  and  sufficient  clearance.  The  cutter  must 
also  be  positioned  square  with  the  head,  perfectly  in  line 
with  the  travel  of  the  stock,  and  needless  to  say,  it  must  be 
secured  in  a  rigid  manner  so  there  will  be  no  chattering  or 
vibration  when  in  action. 

Saw  tooth  splitting  cutters  like  A  and  D,  Fig.  49,  should 
be  of  such  shape  that  the  forward  or  first  teeth  are  pro- 
portionately lower  than  those  at  the  middle  and  back,  in 
order  that  the  cutting  will  be  evenly  distributed  among  all 
the  teeth.  Otherwise,  a  few  forward  teeth  of  each  splitter 


82 


MACHINE  HOLDER  PRACTICE. 


will  carry  most  of  the  strain  and  do  most  of  the  cutting, 
with  the  result  that  the  cutter  will  heat  rapidly  and  not 
stand  up  to  heavy  work  at  fast  feed. 

While  the  examples  of  multiple  work  appearing  in  Figs. 
46  and  48  show  only  simple  moldings  in  pairs,  each  mem- 
ber of  which  is  the  same  size  and  shape,  it  does  not  follow 
that  all  moldings  run  in  multiples  are  or  must  be  made  in 
this  manner.  There  is  really  no  limit  to  the  variety  of  com- 
binations that  can  be  worked  out.  Entirely  different  pat- 


Fig1.  51.     Showing  how  an  extra  molding-  can  sometimes  be  saved 
by  under-cutting. 

terns  can  be  paired  if  desired  and,  instead  of  running  mold- 
ings in  twos,  the  machine  can  be  set  up  for  making  three, 
four,  five  or  more  strips  simultaneously  from  one  piece  of 
stock.  So  far  as  the  mechanical  part  of  the  operation  is 
concerned,  one  might  run  12-in.  stock  in  gangs  of  nar- 
row moldings  right  along,  but  considered  from  a  business 
standpoint,  this  practice  is  rank  folly  on  account  of  the 
high  cost  of  wide  lumber. 

Sometimes  thin  moldings  are  run  in  gangs  but  in  double 
thicknesses,  and  they  are  put  thru  a  band  resaw  afterward 
to  separate  them.  This  practice  is  occasionally  followed  in 
the  manufacture  of  screen  moldings  and  other  cheap  work. 
Other  patterns  are  run  double  thickness  and  split  apart 
with  a  circular  saw  attachment  on  the  rear  of  the  molder. 

SAVING  AN  EXTRA  MOLDING. 

When  the  profile  of  any  single  molding  13/16-in.  or 
more  in  thickness  is  such  that  one  or  both  face  corners 
must  be  cut  away  to  a  considerable  extent,  it  is  sometimes 


MAKING  MOLDINGS  IN  MULTIPLES.  83 

possible  to  save  a  small  molding  or  strip  by  doing  a  little 
under-cutting  as  shown  at  A,  B,  and  C,  Fig.  51.  This 
method  of  making  moldings,,  however,  is  not  practiced  very 
extensively  and  it  is  not  recommended  excepting  on  long 
runs  of  softwood  molding  when  good  lumber,  practically 
free  from  knots,  is  worked.  The  method  is  entirely  practi- 
cal and  is  the  means  of  producing  or  rather  saving  an  extra 
strip  of  small  molding  which  would  otherwise  be  cut  into 
shavings.  If  the  principal  molding  of  the  cluster  is  made 
face  down  as  shown  in  the  examples  in  Fig.  51,  it  is  gen- 
erally advisable  and  often  necessary  to  fasten  wood  block- 


Fig-.  52.     Combination  head  for  splitting-  and  planing. 

ing  onto  the  rear  guides  and  back  table  in  order  to  hold 
the  moldings  solidly  in  place  and  prevent  them  from  caving 
in  to  the  knives  as  they  leave  the  bottom  head. 

One  more  method  of  gaining  an  extra  strip  of  molding 
without  the  use  of  additional  stock  is  to  saw  out  the  rab'bett 
of  rabbetted  patterns,  such  as  jambs,  screen  *door  stock,  etc., 
instead  of  cutting  it  into  shavings,  with  knives.  The  strips 
are  sawed  out  with  either  circular  saws,  splitting  cutters,  or 
special  cutterheads  in  which  square  or  round-head  sections 
carrying  knives  are  combined  with  circular  saws,  or  parts 
of  saws.  One  type  of  special  head  for  this  purpose  appears 


MACHINE  HOLDER  PRACTICE. 


will  carry  most  of  the  strain  and  do  most  of  the  cutting, 
with  the  result  that  the  cutter  will  heat  rapidly  and  not 
stand  up  to  heavy  work  at  fast  feed. 

While  the  examples  of  multiple  work  appearing  in  Figs. 
46  and  48  show  only  simple  moldings  in  pairs,  each  mem- 
ber of  which  is  the  same  size  and  shape,  it  does  not  follow 
that  all  moldings  run  in  multiples  are  or  must  be  made  in 
this  manner.  There  is  really  no  limit  to  the  variety  of  com- 
binations that  can  be  worked  out.  Entirely  different  pat- 


Fig.  51.     Showing  how  an  extra  molding-  can  sometimes  be  saved 
by  under-cutting. 

terns  can  be  paired  if  desired  and,  instead  of  running  mold- 
ings in  twos,  the  machine  can  be  set  up  for  making  three, 
four,  five  or  more  strips  simultaneously  from  one  piece  of 
stock.  So  far  as  the  mechanical  part  of  the  operation  is 
concerned,  one  might  run  12-in.  stock  in  gangs  of  nar- 
row moldings  right  along,  but  considered  from  a  business 
standpoint,  this  practice  is  rank  folly  on  account  of  the 
high  cost  of  wide  lumber. 

Sometimes  thin  moldings  are  run  in  gangs  but  in  double 
thicknesses,  and  they  are  put  thru  a  band  resaw  afterward 
to  separate  them.  This  practice  is  occasionally  followed  in 
the  manufacture  of  screen  moldings  and  other  cheap  work. 
Other  patterns  are  run  double  thickness  and  split  apart 
with  a  circular  saw  attachment  on  the  rear  of  the  molder. 

SAVING  AN  EXTRA  MOLDING. 

When  the  profile  of  any  single  molding  13/16-in.  or 
more  in  thickness  is  such  that  one  or  both  face  corners 
must  be  cut  away  to  a  considerable  extent,  it  is  sometimes 


MAKING  MOLDINGS  IN  MULTIPLES.  83 

possible  to  save  a  small  molding  or  strip  by  doing  a  little 
under-cutting  as  shown  at  A,  B,  and  C,  Fig.  51.  This 
method  of  making  moldings,  however,  is  not  practiced  very 
extensively  and  it  is  not  recommended  excepting  on  long 
runs  of  softwood  molding  when  good  lumber,,  practically 
free  from  knots,  is  worked.  The  method  is  entirely  practi- 
cal and  is  the  means  of  producing  or  rather  saving  an  extra 
strip  of  small  molding  which  would  otherwise  be  cut  into 
shavings.  If  the  principal  molding  of  the  cluster  is  made 
face  down  as  shown  in  the  examples  in  Fig.  51,  it  is  gen- 
erally advisable  and  often  necessary  to  fasten  wood  block- 


Fig-.  52.     Combination  head  for  splitting-  and  planing. 

ing  onto  the  rear  guides  and  back  table  in  order  to  hold 
the  moldings  solidly  in  place  and  prevent  them  from  caving 
in  to  the  knives  as  they  leave  the  bottom  head. 

One  more  method  of  gaining  an  extra  strip  of  molding 
without  the  use  of  additional  stock  is  to  saw  out  the  rab'bett 
of  rabbetted  patterns,  such  as  jambs,  screen*  door  stock,  etc., 
instead  of  cutting  it  into  shavings,  with  knives.  The  strips 
are  sawed  out  with  either  circular  saws,  splitting  cutters,  or 
special  cutterheads  in  which  square  or  round-head  sections 
carrying  knives  are  combined  with  circular  saws,  or  parts 
of  saws.  One  type  of  special  head  for  this  purpose  appears 


84 


MACHINE  HOLDER  PRACTICE. 


in  Fig.  52.  This  is  used  on  the  side  spindle  to  surface  the 
edge  and  saw  under  the  strip  which  is  saved.  The  practice 
of  saving  strips  of  molding,  as  described,  is  followed  quite 
extensively  in  factories  making  screen  doors,  bee  hives,  and 
other  stock  products  which  are  manufactured  in  large  quan- 
tities. In  Fig.  53,  there  is  shown  the  manner  in  which  a 


INSIDE  HEAD 


BOTTOM  HEAD 


Fig.  53.  One  method  of  making-  screen  door  stock  and  sav- 
ing- the  molding.  Fig.  54.  Machine  set-up  for  making  molding 
in  Fig.  53. 

strip  of  screen  molding  is  sawed  from  the  corner  of  screen 
door  stock  as  the  material  feeds  thru  the  machine.  This 
operation  in  itself  is  simple  indeed,  but  when  the  specifica- 
tions call  for  a  small  groove  Gr  in  the  bottom  of  the  fin- 
ished rabbett  the  proposition  is  not  quite  so  easy.  This 
groove,  by  the  way,  is  milled  for  the  purpose  of  receiving  the 
wire  and  a  small  strip  of  wood  or  rattan  which  crimps  the 
screen  wire  securely  in  place.  The  usual  method  of  milling 
the  groove  without  resorting  to  an  extra  operation  and  an 
extra  handling  appears  in  Fig.  54,  A  small  diameter  groov- 
ing saw  C  is  suitably  mounted  directly  above  the  rear 


MAKING  MOLDINGS  IN  MULTIPLES.  85 

table  and  driven  by  a  separate  countershaft,  a  motor,  or  by 
a  short  belt  from  a  narrow  pulley  alongside  the  bottom  head 
pulley.  The  strip  of  screen  molding  is  sprung  upward, 
after  being  cut  free  from  the  stock  by  a  saw  or  cutter  on  the 
inside  head.  As  the  strip  advances  over  the  inclined  bar  B, 
it  clears  cutter  C,  and  when  finished  it  either  falls  into  a 
trough  or  is  taken  away  by  the  helper.  The  cutter  can  be 
rotated  in  either  direction  because  it  makes  a  very  light  cut. 
The  yoke  which  carries  the  small  grooving  saw  is  removable 
so  that  it  can  be  detached  after  a  job  of  this  kind  is  com- 
pleted. 


Gang-  of  splitting  saws  mounted  on  self-centering  sleeve  for 
use  on  molder  spindle.  The  saws  are  separated  by  spacing- 
collars. 


CHAPTER  XI. 

MISCELLANEOUS   HOLDER  WORK. 

There  is  a  vast  amount  of  special  work  produced  on 
molders  in  various  kinds  of  wood-working  factories  and 
many  freak  jobs  are  occasionally  done  in  jobbing  mills  in 
emergencies,  but  since  the  scope  of  each  of  these  individual 


\ 


Fig.  55.     Divided  rip  saw  for  use  on  top  or  bottom  spindle. 

jobs  is  so  limited  it  is  hardly  worth  describing  all  of  them  in 
detail.  For  example,  there  are  cases  where  rope  or  twist 
molding  has  been  successfully  made  by  turning  round  mold- 
ing spirally  by  hand  in  a  form  clamped  diagonally  over  the 


MISCELLANEOUS  MOLDER  WORK.  87 

bottom  head  of  the  molder.  An  occasion  seldom  arises, 
however,  for  doing  such  unusual  work  in  this  crude  man- 
ner. Twist  molding  of  practically  any  design  and  pattern 
is  now  made  in  factories  where  regular  twist  machines  are 
in  operation.  A  few  examples  of  special  work  which  are 
perhaps  of  more  general  interest  follow : 

RIPPING  WITH  DIVIDED  SAWS  IN  GANGS. 

Divided  rip  saws  like  Fig.  55,  are  sometimes  used  be- 
tween'large  collars  on  the  bottom  spindle  of  a  molder  for 
ripping  lattice,  parquetry  strips,  and  other  light  work. 
The  strips  are  first  planed  with  the  top  head  and  then 
ripped  in  the  same  operation.  Pine-toothed,  hollow-ground 
saws  are  best  for  this  work  because  they  cut  smoothly  and 
are  easier  to  fit  and  keep  in  order.  Plain  spring  set,  or 
swaged  saws  can  be  used  with  good  results,  however,  if  they 
are  carefully  fitted.  The  halves  are  held  together  with 
keys  which  are  fastened  on  one  side,  as  shown.  Being 
divided,  the  saws  can  be  put  on  and  removed  at  any  time 
without  disturbing  the  boxes. 

RUNNING  HEAVY  MOLDED  CASKET  SIDES. 

Wide  casket  sides,  having  a  narrow  piece  glued  on  the 
face  side  next  to  the  bottom  edge  to  make  the  base,  and, 


INFEED  ROLL 


MOLDER  BED 


Fig.  56.     Position  of  top  rolls  for  feeding  special  casket  sides. 

sometimes  a  piece  at  the  top  to  make  a  heavy  ledge,  are 
run  face  up  with  the  thick  edge  next  to  the  guide  rail. 


88 


MACHINE  HOLDER  PRACTICE. 


Altho  full-width  top  feed  rolls  can  be  used  for  this  work, 
better  results  are  obtained  by  the  use  of  narrow  rolls  which 
ride  only  on  the  thin  part,  as  shown  in  Fig.  56.  A  sec- 
tional chipbreaker  is  also  used  so  the  thin  part  of  the  sides 
can  be  held  down  firmly  to  the  machine  bed  as  the  sides 
advance  to  the  top  head.  In  running  wide  material,  the 
under-side  of  the  pressure  bar  should  be  grooved,  recessed, 
or  cut  away  at  all  points  except  where  pressure  is  absolutely 
needed.  This  precaution  serves  to  reduce  excessive  fric- 
tion between  the  molding  and  the  pressure  bar.  Other- 
wise the  material  will  not  feed  freely,  but  will  stick  in  the 
machine  or  tend  to  "crawl"  away  from  the  guide  rail. 

MAKING  GLUE  JOINTS. 

Edge  glue  joints  can  be  made  on  a  molder  on  condition 
that  the  stock  is  fairly  straight  and  of  uniform  width.  In 
one  casket  factory  the  1x10  common  cedar  for  adult-size 


INSIDE  OR 
\JOINTING  HEAD 


J=  1 

~^- 

± 

-  —  =^      V  J    D                      a 
B.  H                                               T-  H- 

I  ' 

a                    a   7 

Fig.  57. 


Line-up  of  guide  rail  and  inside  head  for  making 
slack-center  glue  joints. 


casket  bottoms  is  successfully  edge  jointed  on  a  molder. 
The  stock  is  first  roughly  cut  to  about  6-ft.  in  length  and 
then  sent  to  a  15-in.  molder  where  the  pieces  are  surfaced 
two  sides,  jointed  and  sized  to  exact  width  in  one  operation. 
A  re ver sable  tongue  and  groove  joint  is  worked  on  one 
edge  with  the  inside  head  which  is  set  to  take  a  full  %-in. 
cut.  The  stock  is  of  such  size  that  it  does  not  spring  out  of 


MISCELLANEOUS   HOLDER  WORK.  89 

true  in  the  machine  provided  the  latter  is  in  proper  align- 
ment and  adjusted  to  feed  freely.  Accurate  setting  of  the 
jointing  (inside)  head,  guide  rail,  and  outside  guides  is 
particularly  important.  In  actual  practice  the  operator 
employs  a  little  trick  to  make  the  joints  slack  or  slightly 
concave  in  the  center  to  offset  the  possibility  of  some  joints 
being  full  in  the  center.  The  trick  lies  in  the  adjustment 
of  the  guide  rail  back  of  the  jointing  head,  and  it  is  the 
same  scheme  that  is  used  to  make  slack  center  joints  on  an 
ordinary  glue  jointer.  A  continuous  back  guide  rail  is  used, 
and  at  the  rear  of  the  machine  it  is  clamped  slightly  out  of 
line  as  shown  exaggerated  at  A,  Fig.  57.  This  method  of 
jointing,  planing,  and  sizing  material  to  width  in  one  oper- 
ation effects  considerable  saving  in  manufacturing  costs  and 
the  idea  can  often  be  applied  to  other  kinds  of  work  with 
good  results. 

RUNNING  VERY  THIN  WORK. 

In  order  to  successfully  run  real  thin  patterns,  one  must, 
as  a  rule,  resort  to  a  method  similar  to  that  used  in  plan-- 
ing thin  veneer,  that  is,  run  it  on  a  hardwood  board.  The 
board  is  fed  thru  the  machine  with  the  thin  material  on 
top  in  practically  the  same  way  that  a  form  is  used.  Ma- 
terial can  be  planed  as  thin  as  1/32-in.  in  this  way  because 
the  boards  support  it  as  it  passes  thru  the  machine. 

MILLING  A  TAPERED  CHANNEL  IN  WOOD  DRAINS. 

A  molder  on  which  the  bed  is  stationary,  and  the  top  head 
and  rolls  are  adjustable  vertically,  can  be  used  for  quite  a 
variety  of  special  work.  A  tapered  channel  can  be  milled 
in  solid  wood,  as  the  stock  feeds  thru  the  machine,  by  gradu- 
ally cranking1  the  head  to  make  a  pointer  follow  a  line 
scribed  on  the  outside  to  correspond  to  the  required  taper. 
Square  pilaster  sides  can  also  be  fluted  up  to  a  point  near 
each  end  by  dropping  the  top  head  to  cut  at  the  proper 
point  and  then  raising  it  when  the  material  has  fed  for- 
ward a  distance  equal  to  the  required  length  of  the  flutes. 


90 


MACHINE  MOLDER  PRACTICE. 


MOLDING  ACROSS  THE  GRAIN. 

In  piano,  furniture  and  novelty  plants,  certain  patterns 
must  be  molded  directly  across  side  and  end  grain.  Piano 
actions  serve  as  a  good  example  of  work  which  must  be 
molded  smoothly  and  accurately  crosswise  instead  of 
lengthwise  of  the  grain.  Altho  ordinary  narrow  knives 
are  sometimes  used  in  this  class  of  work,  knives  which  are 
slightly  twisted  or  ground,  and  positioned  so  that  they  make 


AFTER  FIRST  RUN 


Fig.  58.     Method  of  making-  stair  rail  in  two  runs. 

a  shearing  cut  like  tenoner  and  automatic  turning  ma- 
chine knives,  are  the  most  satisfactory  because  they  do  not 
pick  up  nor  tear  out  the  grain.  Circular  milled  cutters, 
with  an  angular  face-bevel  instead  of  the  usual  straight  face, 
are  also  suitable  for  molding  across  the  grain,  especially 
when  they  are  accurately  ground  so  that  all  wings  do  an 
equal  share  of  cutting.  Usually  the  material  to  be  run 
crosswise  of  the  grain  is  planed  and  sawed  into  blocks 
which  are  glued  up  in  lengths  suitable  for  feeding  thru  a 
molder.  In  many  cases  the  regular  chipbreaker  is  dis- 
pensed with  and  hardwood  springs  are  set  right  up  against 
the  cutting  knives  at  the  point  where  they  begin  cutting, 
while  the  point  of  a  wood  pressure  bar  is  set  as  close  as 


MISCELLANEOUS  MOLDER   WORK.  91 

possible  to  the  point  where  the  molding  leaves  the  cutter- 
head.  The  object  in  setting  the  chipbreaker  and  pressure 
bar  so  close  is  to  reduce  the  open  gap  for  the  cutters  to  a 
minimum  and  thereby  prevent  chipping  and  tearing  of 
grain.  It  is  the  same  principle  that  is  employed  in  shaper 
work, 

RUNNING  STAIR  RAIL. 

A  good  rule  to  follow  in  making  stair  rail  is  to  place  the 
greatest  width  flatwise  and  the  heaviest  cut  to  the  top  head. 
This  is  why  so  many  patterns  of  stair  rail  are  run  on  their 
sides  instead  of  straight  up.  In  the  latter  case,  the  bot- 
tom of  the  rail  is  turned  to  the  guide  rail.  When  large 
quantities  of  standard  stair  rail  are  made,  the  work  is  often 
performed  in  one  operation,  but  when  there  is  only  a  small 
amount  to  make,  or  if  the  bottom  head  is  too  light  to  make 
the  finish  cut,  the  rail  is  made  in  two  operations.  On 
short  runs  two  operations  are  often  really  more  economical 
than  one.  For  instance,  suppose  a  rail  is  the  same  shape 
on  both  sides.  One  set  of  knives  on  the  top  head  will  serve 
for  both  runs  without  any  change  except  to  adjust  the  head 
for  thickness.  By  making  the  rail  in  two  operations  the 
set-up  time  alone  is  reduced  to  less  than  half.  If  the  pat- 
tern is  such  that  new  knives  are  required  a  further  saving 
is  naturally  effected  by  working  it  in  two  operations.  In 
Fig.  58  is  shown  a  simple  stair  rail  and  the  method  of 
making  it  in  two  operations.  After  the  first  run  the  rail 
appears  like  D,  Fig.  58,  then  it  is  turned  jend  for  end  and 
run  on  a  light  hardwood  form- as  shown  at  E,  Fig.  58. 
During  the  second  run  the  bottom  of  the  rail  is  grooved  for 
balusters  with  the  inside  head. 

MAKING   CHURCH   SEATING. 

On  account  of  its  great  width  and  depth  of  cut,  church 
seating  is  generally  made  on  a  heavy  18-in.  molder.  While 
ordinary  knives  and  heads  can  be  used  for  molding  church 
seating,  a  special  head  with  detachable,  close-fitting  formed 


92  MACHINE  HOLDER  PRACTICE. 

lips  serves  the  purpose  much  better  because  it  effectually 
prevents  all  chipping  and  torn  grain.  Heads  of  this  type, 
of  course,  are  only  recommended  for  factories  that  produce 
large  quantities  of  church  seating  or  other  standard  work. 
The  four  corners  of  the  head  are  milled  out  to  receive  four 
formed  chipbreakers  like'M,  Fig.  59,  which  are  ground  to 


Fig.   59.      Special  head,  rabbetted  to  receive  formed  lips  like  M. 

match  the  molding  knives.  These  formed  lips  or  chip- 
breakers  are  really  reversed-knives  without  slots  and  are 
screwed  down  to  the  head  with  flat-head  machine  screws. 
The  cutting  knives  are  bolted  firmly  with  planer  bolts 
threaded  down  into  the  solid  head.  The  cutting  edge  of  the 
knives  is  set  out  only  about  1/16-in.  beyond  the  correspond- 
ing edge  of  the  formed  lips.  The  result  is  very  smooth 
work,  no  torn  grain,  and  less  strain  on  the  knives.  The 
formed  lips  for  church  seating  are  detachable  and  can  be 
replaced  with  straight  steel  lips  or  lips  of  some  other  shape, 
if  so  desired. 


CHAPTEE  XII 

HIGH-SPEED    MOLDER    WORK. 

The  modern  high-speed  molder,  with  massive  frame, 
large  journals,  wide  pulleys,  improved  feed  mechanism  and 
multiple  bit,  self-centering  slip-on  heads  carrying  high- 
speed steel  cutters,  represents  the  acme  of  perfection  in  the 
development  of  wood-molding  machines.  Like  all  other 
fast-feed  machines,  it  is  designed  to  meet  the  urgent  de- 
mand for  increased  production  and  a  reduction  in  the  unit 
cost  of  manufacturing  moldings. 

Altho  the  regulation,  square-head  molder  with  feeds 
ranging  from  15-ft.  to  40-ft.  a  minute  was,  and  still  is,  a 
satisfactory  machine  for  making  short  runs  of  odd  and 
special  moldings,  millmen  recognized  long  ago  the  need  of 
a  faster-feed  machine  for  making  standard  patterns  in  large 
quantities.  When  fast-feed  planers  and  matchers  made 
their  first  appearance  some  years  ago,  and  startled  the 
lumber  worlcl  by  successfully  producing  high-grade  dressed 
lumber,  flooring,  ceiling,  etc.,  at  feeds  of  150-ft.  to  300-ft. 
a  minute,  stock  moldings  were  still  being  run  at  slow  feeds 
and  no  better  or  more  rapid  means  of  manufacturing  mold- 
ing was  offered  to  the  trade  until  a  few  years  later. 

The  problem  of  bringing  out  a  fast-feed  molder  suitable 
for  a  variety  of  work  naturally  involved  the  overcoming  of 
more  serious  obstacles  than  those  encountered  in  perfecting 
fast-feed  planers  and  matchers.  The  principles  upon  which 
the  success  of  the  fast-feed  idea  is  based  were  the  same  in 
both  cases,  but  the  irregular  shapes  and  deep  cuts  in 
molded  work  made  it  necessary  to  devise  different  types  of 
multiple  bit  heads  and  cutters,  different  knife  setting  and 
truing  devices,  etc.,  than  those  employed  on  other  kinds  of 
fast-feed  machines.  All  difficulties,  however,  were  sur- 
mounted in  time  and,  after  passing  thru  the  usual  experi- 


MACHINE  MOLDER  PRACTICE. 


HIGH-SPEED  HOLDER  WORK. 


95 


mental  stage,  the  high-speed  or  rather  fast- feed  molder 
reached  a  degree  of  perfection  equal  to  that  of  the  present- 
day  fast-feed  matcher. 

AN  EXPLANATION  OF  MOLDER  SPEEDS. 

The  underlying  or  basic  principle  which  makes  fast-feeds 
possible  is  to  get  more  knives  into  action  at  each  revolution 
of  the  cutterhead.  Those  who  have  given  the  subject  more 
than  casual  attention  know  that  when  a  square-head  molder 


One  type  of  six-knife,   slip-on  round  head  for  top  or  bottom 
spindle  of  molder. 

is  set  up  with  ordinary  knives  in  the  customary  manner  and 
put  into  operation,  there  is  only  one  knife  cutting  at  any 
one  part  of  the  stock.  There  may  be  a  dozen  knives  posi- 
tioned around  the  four  sides  of  the  head  but  no  two  cut 
alike  unless  by  rare  coincidence.  This  statement  can  be 


96 


MACHINE  HOLDER  PRACTICE. 


verified  any  time  by  observing  the  dust  marks  on  the  back 
edge  of  the  knives  after  feeding  a  piece  of  material  a  few 
inches  past  the  cutting  heads.  If  only  one  knife  of  a  kind 
strikes  the  material  at  each  revolution  of  the  head,  there 
is  only  one  knife  cut  per  revolution ;  hence,  a  molder  head 
lotating  3,600  r.p.m  makes  3,600  knife  cuts  a  minute. 


Self-centering  "vise  grip"   type  of  profile  head  carrying-  high- 
speed steel,  milled-to-pattern  cutters. 

Feeding  stock  at  the  rate  of  25-ft.  a  minute  (300-inches  a 
minute)  gives  a  ratio  of  3,600  :300  or  12  knife  cuts  per 
lineal  inch  which,  when  other  conditions  are  right,  results 
m  a  comparatively  smooth  finish.  Suppose  the  feed  is  in- 
creased to  30-ft.  a  minute  (360-inches  a  minute)  it  gives 
a  ratio  of  3,600:360  or  10  knife  cuts  to  the  inch,  which 
means  each  knife  will  cut  away  a  little  more  wood,  resulting 
in  slightly  more  chipping  and  deeper  knife  marks  on 
the  surface  of  the  molding.  The  work  may  be  passable 
but  will  not  be  as  smooth  as  that  run  at  the  rate  of  25-ft. 
a  minute.  The  cutterhead  speed  might  be  increased  to  4,000 


HIGH-SPEED  MOLDER  WORK.  97 

r.p.m.  which,  with  a  feed  of  30-ft.  a  minute,  would  give 
about  11  knife  marks  to  the  inch,  but  it  is  unwise  to  run 
molder  cutterheads  at  such  high  speed  because  of  possible 
vibration,  heating  of  boxes,  and  the  difficulty  in  obtaining 
a  good  running  balance  with  the  knives  and  bolts. 

The  principle  of  fast-feed  machines  is  to  get  more  knives 
in  action  per  revolution  rather  than  to.  increase  the  revo- 
lutions per  minute  of  the  cutterheads.  Two  knives  cutting 
instead  of  one  doubles  the  number  of  knife  cuts  per  revolu- 
tion, four  knives  increases  the  number  fourfold,  and  six 


Two  universal   chamfer  heads  set  side  by  side.     These  cutters 
may  be  adjusted  to  cut  practically  any  bevel  desired. 

% 

knives  sixfold,  etc.  When  the  number  of  knives  of  a  kind 
on  a  cutterhead  are  doubled  or  increased  four  or  sixfold, 
and  all  of  them  are  brought  into  equal  action  by  means  of 
knife-truing  devices,  described  later,  the  rate  of  feed  is 


98 


MACHINE  HOLDER  PRACTICE. 


HIGH-SPEED  MOLDER  WORK.  99 

increased  in  direct  proportion  without  affecting  the  quality 
of  work. 

There  are  four  factors,  each  bearing  relationship  to  the 
other,  which  when  taken  together,  determine  the  quality 


A  three-disc,  combination  head  for  grooving1  heavy  planks,  etc. 
Notice  enlarged  section  in  middle. 

and  quantity  of  work  that  can  be  turned  out  on  a  molding 
or  planing  machine.  They  are  the  speed  of  the  cutterhead 
in  r.p.m. ;  the  speed  of  the  feed  in  feet  or  inches  per  min- 
ute ;  the  number  of  knives  in  action  on  the  head ;  the  num- 


100  MACHINE  MOLDER  PRACTICE. 

ber  of  knife  marks  (whether  visible  or  not)  per  inch  on 
the  finished  molding.  The  relationship  which  these  factors 
bear  to  each  other  is  expressed  by  the  following  rule :  The 
product  of  the  r.p.m.  of  a  cutterhead  multiplied  by  the 
number  of  knives  in  action,  divided  by  the  rate  of  feed  in 
inches  per  minute  equals  the  number  of  knife  marks  per 
lineal  inch  on  the  finished  work.  Perhaps  a  more  clear 
way  to  express  this  relationship  is  by  equation  form,  as 
follows : 

E=r.p.m.  of  head. 

F=rate  of  feed  in  inches  per  minute. 

K=number  of  knives  on  head. 

X=number  of  knife  cuts  per  lineal  inch. 

EK  EK  FX  FX 

X= F= E=—  K=— 

F  X  K  E 

Expressed  in  proportion  this  amounts  to 

F        E 
EK=FX     or 

K       X 

Note:  For  the  benefit  of  those  not  versed  in  algebra,  the  times 
sign  (x)  is  omitted  between  letters  which  are  to  be  multiplied,  RK 
meaning1  R  x  K;  FX  meaning  F  x  X,  etc. 

Xow,  by  substituting  known  values  for  any  three  of  the 
letters  in  the  above  equations,  the  third  can  be  calculated  by 
the  simple  formula  given  herewith,  and  one  can  determine 
all  the  factors  upon  which  depends  the  quality  of  work, 
and  the  speed  at  which  it  is  run.  That  is,  exact  calculations 
can  be  made  as  to  the  speed  of  cutterheads,  speed  of  feed, 
number  of  knives  in  action,  and  the  degree  of  finish  (num- 
ber of  knife  marks  or  cuts  to  the  inch).  This  eliminates 
"cut  and  try"  methods  and  the  usual  experimenting  with 
different  size  pulleys  and  speeds  which  take  up  so  much 
valuable  time,  spoil  good  lumber,  and  entail  extra  expense 
for  labor  and  supplies. 


HIGH-SPEED  MOLDER  WOliK.  '101 

When  making  calculations  as  tc ••  tbfc  {V^sibiii'  us  ot'-vjirj- 
ous  molding  and  planing  machines,  as  previously  described, 
one  must  keep  within  certain  limitations  in  regard  to  the 
figures  used  to  represent  the  speed  of  heads,  rates  of  feed, 
and  the  number  of  knife  cuts  per  lineal  inch  of  stock.  No 
hard  and  fast  rules  can  be  laid  down  in  this  matter  but  the 
following  recommendations  are  based  upon  results  of  ex- 


i 


Special  combination  head  for  working  one  of  the  many  unique 
patterns  run  at  the  National  Cash  Register  Company's  plant. 

periments  and  common  practice  in  mills  thruout  the 
country:  3%-in.  square  heads — :3,700  to  4,000  r.p.m. ; 
41/4-in.  square  heads— 3,300  to  3,600  r.p.m.;  6-knife 
round  heads — 3,000  to  3,200  r.p.m. ;  8-knife  round  heads 
—2,800  to  2,900  r.p.m. 

Eates  of  feed,  especially  on  fast-feed  machines,  vary  ac- 
cording to  the  quality  of  finish  desired,  the  kind  of  machine 
and  its  equipment,  and  the  facilities  available  for  getting 
material  to  and  from  the  machine.  A  great  deal  of  pine 
and  fir  flooring  of  good  grade  is  made  on  fast-feed  matchers 


102 


MOLDER  PRACTICE. 


HIGH-SPEED  HOLDER  WORK.  103 

equipped  with  automatic  feeding  tables,  at  speeds  ranging 
up  to  300-ft.  a  minute,  but  molding  is  seldom  run  at  half 
this  speed  on  fast-feed  molders.  In  fact,  the  average  high- 
speed molder  is  generally  rated  to  feed  up  to  or  near  100- 
ft.  a  minute  which  is  about  four  times  as  fast  as  high-grade 
molding  is  made  on  the  old-style,  square-head  machine. 


m 


Profile  beader  head  fitted  -with  high-speed  steel,  formed  knives. 
Used  to  work*  beaded  ceiling',   etc. 

Faster  feeds  are  possible,  but  not  always  practicable,  because 
they  do  not  give  the  operator  sufficient  thne  to  properly 
grade  and  turn  the  stock  as  he  -feeds  it. 

There  is  also  a  limit  to  the  number  of  knife  cuts  per- 
missible to  the  lineal  inch  of  feed.  Generaly  speaking, 
the  more  knife  cuts  per  inch,  the  smoother  the  work,  but 
there  is  a  recognized  limit  beyond  which  it  is  unprofitable 
to  go.  This  limit  is  about  18  cuts  to  the  inch.  If  there  are 
more  cuts  than  this  the  knives  do  not  "bite"  into  the  ma- 


104  MACHINE  HOLDER  PRACTICE. 

terial  deep  enough  to  cut  efficiently  and  the  result  is  a 
rubbing,  scraping  action  which  rapidly  dulls  and  heats  the 
knives.  Anything  between  12  and  18  cuts  to  the  inch  pro- 
duces a  nice  smooth  surface;  10  to  11  cuts  to  the  inch 
often  gives  a  passable  finish,  but  less  than  10  to  the  inch 
invaribly  shows  the  knife  marks  badly,  in  addition  to  chip- 


JlL 


A   groove   head   for   flooring.      Notice   the   method   of   adjusting 
and  locking  the  groover  and  its  holder. 

ping  and  tearing  the  grain  wherever  knots  or  cross-grain 
are  encountered.  This,  in  substance,  is  the  possible  and  im- 
possible, the  practical  and  impractical  in  molder  speeds  and 
quality  of  finish.  It  reduces  what  formerly  has  been  more 
or  less  an  uncertainty  and  mystery  to  a  simple  matter  of 
true  facts  and  figures. 

CUTTERHEADS  AND  GENERAL  EQUIPMENT. 

High-speed  molders  are  built  in  both  inside  and  outside 
models.     The  inside  type  is  constructed  with  four,   five, 


HIGH-SPEED  MOLDER  WORK.  105 

or  six  heads  and  usually  fitted  with  permanent  round  top 
and  bottom  heads  or  cylinders,,  each  carrying  four  or  six 
knives,  as  desired.  The  top  and  bottom  profile  arbors  at 
the  rear  end  carry  interchangeable  heads  for  irregular 
work.  Four-side  slotted  heads  may  be  used  on  the  aibors 
for  special  work,  using  ordinary  cutters  at  a  slower  feed. 
Heads  carrying  cutters  for  fast-feed  work  are  of  special 
design  and.  possess  the  self-centering  slip-on  feature  which 
permits  fitting  them  up  completely  in  the  grinding  room 
while  the  machine  is  in  service  on  other  work.  The  cutters 
are  made  of  high-speed  steel  ground  to  shape  in  the  usual 
manner,  or  milled  on  the  back  to  the  profile  of  the  mold- 


Fig\   60.     Transverse  T-slot  head  carrying1  formed   knives  for 
multiple  work. 

ing,  as  shown  in  Fig.  60.  In  either  case,  the  cutting  edges 
should  be  jointed  while  in  motion  to  bring  them  all  into 
exactly  the  same  cutting  circle.  Each  kind  and  type  of 
cutter  has  its  specific  advantages.  When  there  is  a  large 
quantity  and  wide  range  of  work  it  is  often  profitable  to 
have  machines  and  equipment  of  different  kinds  and  makes, 


106 


MACPIINE  MOLDEK  PRACTICE. 


each  selected  with  a  view  of  its  adaptability  for  certain 
lines  of  work.  There  are  machines  which  have  a  much 
wider  range  than  others  and  consequently  can  be  used  for 


Fig-.  61.     One  type  of  knife-setting-  jig  for  setting  straight  thin 
steel  knives  on   round  heads. 

a  greater  variety  of  work,  yet  for  some  particular  kinds, 
the  machine  with  the  lesser  range  is  more  satisfactory  and 
efficient. 

In  selecting  cutterhead  equipment,  it  is  advisable  that 
every  arbor  for  slip-on  heads  should  be  the  same  size,  re- 
gardless of  whether  the  machine  is  a  molder  or  matcher. 
Top,  bottom,  side,  and  profile  arbors  should  be  exactly 


HIGH-SPEED  MOLDER  WOttfC.  10? 

uniform  size.  All  side-head  sleeves  and  collars  should  re- 
ceive all  cutterheads  and  discs,  irrespective  of  the  type. 
This  is  easily  accomplished  as  manufacturers  will  fit  ma- 
chines with  any  size  arbor  and  furnish  heads  and  discs 


Fig.    62.     Radial   gage   for   setting-  knives   on   square,    round,    or 
three-wing-  heads. 

likewise.  The  impoitance  of  this  uniform  equipment  can- 
not be  overestimated.  It  eifects  a  great  saving  in  set-up 
time,  cost  of  cutters,  and  first  cost  of  equipment. 

To  obtain  best  results  and  maximum  number  of  pro- 
ductive hours  from  a  fast-feed  molder,  adequate  equip- 
ment must  also  be  provided  for  balancing,  setting,  grinding, 
and  jointing  the  cutters.  Cutters  cannot  be  set  on  round 
heads  or  special  high-speed  heads  with  an  ordinary  molder 
rule.  One  type  of  device  for  accurately  gaging  the  projec- 
tion of  straight  knives  in  round  heads  appears  in  Fig.  61 ; 
another  is  shown  in  Fig.  62.  A  setting  and  balancing  stand 
fitted  with  a  templet  for  setting  irregular  molding  cutters 


108  MACHINE  MOLDER  PRACTICE. 

quickly  and  accurately  on  any  type  of  cutterhead  is  shown 
in  Fig.  63. 

It  is  quite  imperative  that  each  one  of  a  set  of  knives 
placed  in  a  high-speed  head  be  of  the  same  make  (therefore 
uniform  temper  and  grade  of  steel)  the  same  thickness, 
width  and  length,,  and  the  same  bevel  and  weight.  When 
setting  and  clamping  up  a  set  of  knives  in  a  round  slotted 
head,  the  clamp  blocks  should  never  be  set  down  hard 


Fig.  63.     A  stand  for  setting  and  balancing  irregular  cutters  on 
any  kind  of  cutterhead. 

against  any  one  knife  until  all  of  the  knives  are  in  the 
head  and  clamped  down  fairly  tight.  When  the  first  knife 
is  put  in,  lock  it  just  tight  enough  to  hold  it  in  place  until 
all  the  cutters  are  in  the  head,  then  each  one  should  be  ad- 
justed and  the  clamp  screws  set  evenly  until  the  head  has 
been  gone  over  three  or  four  times,  before  the  clamping 


HIGH-SPEED  HOLDER  WORK.  109 

process  is  finished.  If  a  cutter  is  clamped  to  the  limit  at 
once,  while  the  clamp  screws  in  remaining  slots  are  slack, 
uneven  strain  is  set  up  which  sometimes  causes  poor  work 
and  hot  bearings.  Another  method  of  setting  and  clamping 
knives  in  round  heads,  when  making  a  change,  is  to 


Fig.    64.     Jointing-   straight  thin   steel   knives   on   a   round   head 
while  it  is  running  at  full  speed. 

loosen  and  remove  only  one  knife  at  a  time  and  immediately 
replace  the  removed  knife  with  a  sharp  one  and .  tighten 
to  the  limit  before  another  is  ever  loosened.  The  latter 
method  is  a  little  quicker  than  the  former  but  not  always 
practicable. 


110  MACHINE  HOLDER  PRACTICE. 

JOINTING  CUTTERS   ON  HIGH-SPEED  HEADS. 

After  a  set  of  high-speed  knives  are  set  as  accurately  as 
possible  to  get  them  with  the  aid  of  modern  gages  and 
knife-setting  devices,  jointing  at  full  speed  is  the  next 
operation.  Since  jointing  is  the  final  operation  before  the 


Fig.   65.     Jointing  thick  knives  on  square  head. 

head  and  knives  are  placed  in  service,  it  is  a  really  impor- 
tant one  and  must  be  performed  with  great  care  and  skill. 
There  are  special  stands  or  aibors  on  the  market  for  joint- 
ing the  knives  of  slip-on  heads,  and  altho  many  are  in  use, 
opinion  is  divided  among  practical  millmen  as  to  whether 
a  cutterhead  jointed  on  an  arbor  in  the  grinding  room  and 
then  transfered  to  the  machine  will  produce  as  nice  a  finish 
as  a  cutterhead  jointed  light  on  the  machine  spindles. 


HIGH-SPEED  MOLDER  WORK. 


Ill 


When  the  knives  on  cutterheads  are  jointed  on  a  joint- 
ing stand,  the  jointing  arbor,  the  machine  spindles,  and  the 
self-centering  sleeves  in  the- heads  must  all  be  mechanically 


Grinding  straight  knives  with  portable  grinder  which  is 
moved  back  and  forward  on  a  horizontal  dove- tail  slide  or  bar 
secured  rigidly  on  the  yoke  of  the  machine  in  accurate  align- 
ment with  the  cylinder. 

perfect  and  in  tip-top  condition;  otherwise,  the  jointing 
will  never  come  right.  The  jointing  arbor  must  be  the 
same  diameter  as  the  machine  spindles  and  must  run 
smoothly  and  quietly  in  well  lubricated,  massive  boxes  at  a 
speed  corresponding  to  that  of  the  molder  heads.  If  either 


MACHINE  HOLDER  PRACTICE. 


the  jointing  arbor  or  any  of  the  machine  spindles  are  the 
least  bit  out  of  true  or  balance,  or  if  either  has  at  any  time 
been  trued-up  after  having  been  in  service,  the  jointing 
will  not  come  right  when  a  head  is  transferee!  from  one  to 


Fig.    66.     One   type   of  side-head   truing   device   in   position   for 
jointing  a  4-knife  side  head  for  square-edging  thin  stock. 

another.  When  all  of  these  little  things  are  taken  into 
account,  anyone  of  which  will  destroy  a  perfect  jointing,  it 
is  easy  to  understand  why  many  practical  millmen  prefer  to 
joint  cutters  while  the  cutterheads  are  positioned  and 
clamped  on  the  machine  spindles.  A  good  jointing  arbor, 


HIGH-SPEED  HOLDER  WORK. 


113 


however,  is  of  inestimatable  value  in  every  grinding  room 
whether  used  for  jointing  cutterheads  or  not.  It  serves  as 
an  excellent  machine  for  testing  the  running  balance  of  all 
slip-on  heads  before  they  are  put  in  service  on  the  ma- 
chine spindles.  By  trying  out  the  heads  for  running  bal- 
ance in  the  grinding  room,  much  valuable  time  is  saved 
because  any  error  in  balance  can  be  detected  and  corrected 
before  the  head  is  put  on  the  machine.  Without  this  pre- 
liminary running  test,  errors  in  balance  are  often  not  dis- 


Fig.   67.     Showing-  formed  stone   and  holder  for  jointing   irreg- 
ular shaped  molder  knives  on  top  or  bottom  head. 

covered,  if  at  all,  until  after  a  head  is  placed  in  service  and 
then  it  is  generally  a  temptation  to  let  it  go.  A  poorly 
balanced  head  on  a  molder  spindle  results  in  poor  work,  hot 
boxes,  and  eventually  worn  bearings. 

Best  results  in  jointing  are  obtained  by  doing  the  work 


114 


MACHINE  MOLDER  PRACTICE. 


while  the  machine  is  warmed  up  and  the  journals  are 
flooded  with  oil.  Joint  lightly  always.  Let  the  "touch"  of 
the  stone,  the  faint  whir  of  the  knives  and  the  appearance 
of  a  small,  dark-red  spot  on  the  end  of  the  stone  tell  when 


Fig-.  68.  Another  type  of  side-head  jointer  and  a  special 
four-wing-,  fast-feed  head  fitted  with  self -centering-  sleeve  and- 
thick  high-speed  steel  cutters. 

the  stone  is  in  action  rather  than  crowd  the  jointing  until 
a  stream  of  red  sparks  fly  into  the  air.  Heavy  jointing  is 
ruinous  because  it  produces  such  a  heavy  heel  that  the 
knives  pound  and  raise  the  grain  instead  of  cutting  freely 
as  they  should.  Also,  the  edge  of  the  cutters  will  burn  if 
the  feed  stops  for  a  moment.  On  the  other  hand,  when  the 
knives  are  jointed  lightly,  they  will  stand  several  jointings 


HIGH-SPEED  HOLDER  WORK. 


115 


(each  of  which  renews  the  cutting  edge)   before  they  re- 
quire regrinding. 

The  device  generally  used  for  jointing  straight  knives 
on  top  and  bottom  heads  at  the  machine  consists  of  a  per- 


Fig-. 


69.        Side-head  jointing-  attachment   in  position  for  joint- 
ing the  formed  cutters  of  a  matcher  head. 


i'ectly  straight  slide  bar  with  a  movable  carriage  accurately 
fitted  thereto  which  carries  a  jointing  stone.    The  slide  bar 


116 


MACHINE  HOLDER  PRACTICE. 


is  set  absolutely  parallel  to  the  cutting  cylinder  and -secured 
rigidly  in  place  so  the  jar  or  vibration  of  the  machine 


Fig-.  70.  Showing-  one  type  of  jointing  device  attached  to 
slide  bar  on  a  jointing-  and  setting-  stand.  Self-centering  heads 
are  set  up,  tried  for  running  balance  and  jointed  at  full  speed 
on  the  stand,  and  then  transferred  to  molder  spindles. 

cannot  effect  it.  During  the  process  of  jointing  the  car- 
riage is  moved  slowly  from  end  to  end  while  the  cutter- 
head  is  revolving  at  full  speed.  Provision  is  made  for 
moving  the  jointing  stone  toward  or  away  from  the  cutter- 


HIGH-SPEED  HOLDER  WORK.  117 

head  and  for  holding  it  firmly  to  the  work,  see  Figs.  64  and 
65. 

The  devices  for  jointing  straight  knives  on  side  heads 
are  similar  to  those  used  for  top  and  bottom  heads.  They 
are  designed  to  be  fitted  to  fhe  machine  frame  at  a  point 
near  each  side  head.  The  jointer-stone  carrier  works  snug- 
ly on  a  vertical  slide  which  sets  parallel  to  the  side  head. 
Both  vertical  and  horizontal  adjustments  are  provided  so 
the  stone  can  be  moved  to-and-from  end  to  end  of  the  slide 
with  ease  and  accuracy,  see  Figs.  66,  68  and  69. 

There  are  two  methods  commonly  used  for  jointing  ir- 
regular shaped  knives.  One  is  to  prepare  a  formed  stone, 
one  edge  of  which  must  be  made  exactly  the  same  shape 
as  the  profile  of  the  molding.  This  formed  stone  is 


A  two-disc  combination  on  self-centering  clamp  sleeve.     Steel 
jointing1  form,   in   two  sections,   appears  at   right. 

.  • 

clamped  in  the  stone  carrier  and  positioned  so  it  lines  up 
exactly  with  the  molding  cutters  on  the  head,  see  Figs.  67 
and  68.  The  carrier  is  then  clamped  fast  to  the  side  bar, 
the  stone  backed  away  from  the  knives,  and  when  the  head 
is  running  full  speed  the  stone  is  advanced  slowly  and 
carefully  until  it  comes  in  contact  with  the  edges  of  the 
whirling  knives.  If  the  knives  have  been  ground  and  set 
with  extreme  care  and  accuracy  a  slight  touch  with  the 


118 


MACHINE  HOLDER  PRACTICE. 


One  type  of  pedestal  head  grinder  for  grinding-  knives  on  self- 
centering1  side  and  profile  heads. 


HIGH-SPEED  HOLDER  WORK.  119 

jointing  stone  will  be  sufficient  to  bring  them  all  into  a 
uniform  cutting  circle  and  make  each  do  an  equal  share 
of  cutting.  The  other  method  consists  of  using  a  device  like 
that  attached  to  the  jointing, stand  shown  in  Fig.  70.  A 
steel  templet  or  pattern  is  clamped  to  the  bar  and  a  pointer 
which  is  arranged  to  travel  on  this  formed  pattern  guides 
a  narrow  jointing  stone  in  such  manner  that  the  exact  pro- 
file of  the  pattern  is  reproduced  on  the  cutters.  The  steel 
patterns  or  templets  can  be  purchased  from  manufacturers 
or  .made  in  the  grinding  room  to  suit  the  form  of  cut  de- 
sired. 

After  the  heads  have  been  fitted  and  positioned  on  their 
arbors,  the  operating  of  a  fast-feed  molder  does  not  differ 
greatly  from  that  of  a  slow-feed  machine.  The  adjusting 
of  the  rolls,  bed,  guides,  and  pressure  bars  is  done  in  prac- 
tically the  same  manner  as  on  the  old-type  machine.  How- 
ever, in  the  case  of  cutterhead  bearings  there  is  a  difference 
because,  when  using  high-speed  heads  and  jointed  cutters,  it 
is  necessary  to  always  have  the  bearings  absolutely  tight  and 
well  lubricated  in  order  to  keep  all  knives  cutting  in  such 
a  manner  that  they  will  produce  a  perfect  surface  on  the 
finished  molding.  The  adjustment  of  the  cutterhead  bear- 
ings, however,  does  not  have  to  he  made  as  often  on  a  fast- 
feed  machine  as  on  the  old-style,  slow-feed  machine  be- 
cause the  journals  are  larger,  caps  are  inoie  securely 
clamped,  and  the  massive  boxes  are  mounted  in  heavy, 
powerful  yokes  which  positively  hold  them  in  place  when 
once  adjusted.  • 

In  making  short  runs  of  special  molding  the  method  used 
is  virtually  the  same  as  on  the  square-head  machine. 
Square  heads  are  slipped  onto  the  spindles  and  clamped  by 
a  self-centering  device.  The  regular  knives  used  in  detail 
molder  work  are  used  in  the  same  way  as  on  the  old-type 
machines  and  about  the  same  rate  of  feed  is  carried. 

The  fast-feed  molder  is  not  confined  to  molding  work 
alone.  Owing  to  its  rigid  design  and  powerful  feed  works, 


120 


MACHINE  MOLDER  PRACTICE. 


m 


HIGH-SPEED  HOLDER  WORK. 


121 


it  will  do  the  ordinary  work  of  both  a  fast-feed  matcher 
and  double  surfacer  and  is  frequently  used  as  such.  It  is 
also  particularly  adapted  for  heavy  work  when  fitted  with 
square  slip-on  heads  on  account  ^of  its  heavy,  powerful  con- 
struction. Since  its  greatest  advantage,  however,  lies  in 
making  long  runs  of  stock  molding,  a  good  supply  of  slip- 
on  heads  and  high-speed  steel  cutters  should  be  kept  on 
hand  at  all  times  to  make  the  various  patterns  of  molding 
regularly  manufactured. 


Inserted,    swaged- tooth    ripping    saw,    with    clamp    collar    and 
self-centering:  sleeve,   for  use  on  a  molder  spindle. 


CHAPTEK  XIII. 

KNIFE  MAKING. 

The  designing  and  making  of  knives  is  an  art  that 
should  be  thoroly  understood  and  mastered  by  every 
mechanic  who  aspires  to  become  a  first-class  molderman. 
Heretofore,  the  opportunities  for  an  apprentice  or  the 
uninitiated  to  learn  knife  making  have  been  few  indeed. 
More  or  less  secrecy  has  always  been  thrown  around  the 
principles  and  correct  practice  of  designing,  shaping,  and 
tempering  molder  knives,  with  the  result  that  many  molder 
operators  are  not  acquainted  with  the  most  up-to-date 
methods  in  this  interesting  and  important  part  of  their 
trade. 

Previous  to  the  advent  of  modern  high-speed  steels, 
which  require  no  heat  treatment,  carbon  steel  was  used  ex- 
clusively for  all  straight  and  irregular  molder  knives.  Be- 
cause of  the  comparative  low  cost,  and  its  satisfactory  per- 
formance on  detail  and  short-order  work,  carbon  steel  is 
still  widely  used  in  woodworking  factories.  It  is  usually 
purchased  in  slotted  blanks  already  cut  to  length  and 
width,  and  beveled  at  the  cutting  edge.  It  also  ccmes  in 
the  form  of  rectangular  bar  steel  of  various  sizes.  As  a 
rule,  steel  for  slotted  knives  is  bought  in  slotted  blanks 
about  %-in.  thick,  while  stock  for  spike  knives  comes  in 
straight  bar  steel  %-in.  to  5/16-in.  thick  and  %-in.  to 
1^-in.  wide. 

When  ordering  knife  steel  for  one  or  more  molders  in  a 
plant,  always  specify  the  same  thickness,  especialy  in  -the 
case  of  bar  steel  for  spike  knives.  It  is  best  to  stick  to 
one  brand  of  steel  as  long  as  that  particular  kind  is  giving 
good  results.  Cheap  steel  is  expensive  at  any  price  and 
should  never  be  considered  under  any  circumstances. 

The   first  thing  in  knife  making   is  to  determine  the 


KNIFE  MAKING.  123 

design  and  size  of  cutter  or  combination  of  cutters  most 
suitable  for  the  work  at  hand.  To  design  a  knife  intelli- 
gently, one  should  know  how  the  molding  is  to  be  run  and 
the  kind  of  wood  that  is  to  be  worked.  The  design  of  a 
single  knife  or  group  of  knives  for  any  particular  pattern 
depends  more  or  less  on  the  number  of  cutterheads  to  be 
employed  and  whether  the  molding  is  to  be  run  face-up 
or  face-down,  flat,  on  edge,  or  at  an  angle,  etc.  If  the 
material  to  be  worked  is  curly-grained  hardwood,  or  if  it 
must  be  molded  across  side  or  end  grain,  the  knives  will,  of 
course,  have  to  be  designed  to  meet  such  conditions.  A 
number  of  common  and  special  knives  for  various  kinds  of 
work  have  already'  been  illustrated  and  described  in  pre- 
ceding chapters.  The  reader  is  further  reminded  of  what 
was  said  in  Chapter  III  about  the  advantages  derived  by 
using  sectional  knives  instead  of  a  single  solid  knife,  es- 
pecially when  making  complicated  patterns.  When  plan- 
ning a  new  knife,  avoid  all  inside  corners  and  other  shapes 
that  require  the  use  of  a  file  for  sharpening  the  cutting 
edge.  A  knife  that  must  be  filed  requires  a  filing  temper, 
therefore  it  cannot  be  depended  on  to  hold  a  sharp  cutting 
edge.  It  dulls  rapidly  and  often  loses  its  true  shape  after 
being  sharpened  a  few  times.  Knives  that  can  be  com- 
pletely ground  to  shape  on  a  wheel  are  more  satisfactory 
in  every  way.  They  are  easier  to  sharpen  and  can  be 
given  a  harder  temper  along  the  cutting  edge. 

Knives  to  cut  wide  sweeping  curves  such  as  shallow 
ogees,  ovals,  etc.,  are  generally  made  in  one  piece  rather 
than  in  sections  because,  in  cases  of  this  kind,  one  knife  is 
easier  to  make  and  set  than  two.  Under  such  circum- 
stances, a  single  solid  knife  is  all  right  provided  the  cut 
is  not  too  deep  and  the  material  is  comparatively  straight 
grained.  Otherwise  the  cut  should  be  divided  between  two 
or  more  knives  positioned  on  different  sides  of  the  head. 

Moldings  which  are  rabbetted  to  overlap  base,  wainscot- 
ing,, or  any  woodwork  %-in.  or  more  thick,  are  almost  in- 


124 


MACHINE  MOLDER  PRACTICE. 


variably  made  as  shown  in  Fig.  71  in  preference  to  the  man- 
ner illustrated  in  Fig.  72,  because  the  former  method  saves 
considerable  lumber.  When  molding  is  turned  at  any  angle, 
and  run  in  this  manner,  the  knives  must  be  designed  accord- 
ingly. Sometimes  by  turning  a  molding,  as  shown  in  Fig. 
71,  a  light  under-cut  is  necessary,  whereas,  if  it  is  made 
like  Fig.  72,  no  under-cutting  is  required.  This  is  another 
case  where  one  must  use  sound  judgment  in  deciding  upon 
the  best  practice  rather  than  follow  any  hard  and  fast  rules. 
Usually  if  there  is  a  large  quantity  of  molding  to  make,  the 


FIG.  71 


Figs.  71  and  72.    Notice  the  saving  in  stock  effected  when  mold- 
ing is  run  as  shown  in  Fig.   71. 

saving  in  lumber  is  of  far  greater  importance  than  the 
little  extra  trouble  required  to  tilt  the  side  head  to  make  a 
small  under-cut. 

Never  attempt  to  make  a  deep  cut  with  a  long,  slender 
knife.  Thick  steel  knives  should  be  used  for  making  deep 
cuts,  and  wherever  possible,  each  knife  should  be  of  extra 
width  to  give  added  strength.  Before  making  a  new  knife 
be  sure  the  steel  blank  is  neither  too  long  nor  too  short  for 
the  head.  If  too  long  it  can  be  cut  down,  of  course,  but  if 
too  short  it  cannot  be  used.  With  the  design  and  size  de- 
termined, the  next  thing  in  order  is  to  grind  the  steel  to 
correct  shape  and  bevel  to  produce  a  knife  which  will  cut 
the  desired  profile.  Knife  shapes  for  bevels  and  straight 
cuts  are  simple  enough,  but  a  knife  -which  will  cut  a  true 
quarter  or  half-round,  a  cove,  ogee,  reverse  ogee,  or  any  ir- 
regular curve,  is  not  so  easily  ground  to  shape  until  one 
has  had  some  practice  at  the  work. 


KNIFE  MAKING. 


125 


Owing  to  the  angle  at  which  knives  on  square  heads  are 
presented  to  the  work,  they  must  project  farther  from  the 
lip  of  the  head  than  the  straight-down  measurement  of  the 
corresponding  cuts  which  they  make,  see  Figs.  73  and  74. 


Figs.    73  and   74.     Notice  how  the  cutting-  angle   changes  with 
depth  of  cut.     Fig.   75.    Method  of  laying  out  molder  scale. 

The  angle  at  which  molding  knives  do  their  cutting  is  by 
no  means  constant,  but  varies  slightly  according  to  size  of 
the  head,  and  considerably  according  to  the  knife  projection 
or  depth  of  cut.  Thus,  in  Fig.  73,  a  surfacing  knife  on  a 
4-in.  head  (reduced  to  scale)  swings  past  the  point  of  its 


126 


MACHINE  HOLDER  PRACTICE. 


deepest  cutting  at  an  angle  of  about  50  degrees,  while  in 
Fig.  74,  a  knife  cutting  %-iii.  deeper  on  the  same  size  head 
finishes  at  an  angle  of  61  degrees. 

The  exact  amount  of  knife  projection  required  for  cut- 
ting different  depths  is  obtained  by  making  a  full-sized 


Fig.  76. 


Method  of  laying  out  knife  profile  with  small  drafting 
outfit. 


layout  of  the  cutterhead  with  at  least  one  knife  in  position, 
see  Fig.  75.  Make  an  allowance  of  about  3/3£-in.,  or 
enough  to  properly  clear  the  knife  bolts,  for  the  projection 
of  surfacing  knives,  as  at  B,  Fig.  75.  From  the  center  of 
the  head  draw  line  C  B  A,  and  on  line  B  A  start  at  B  and 
lay  off  %-in.  divisions  from  a  rule.  Continue  the  knife 
line  K  B  to  D.  Then  with  the  compass  point  at  C,  extend 


KNIFE  MAKING.  127 

the  %-in.  divisions  from  line  B  A  to  the  knife  projection 
line  B  D.  The  divisions  on  B  D  represent  the  true  molder 
scale  for  this  size  head.  Close  examination  of  this  layout 
discloses  the  fact  that  while  all  of  *the  divisions  on  line 
B  D  are  slightly  more  than  %-in.  in  length,  they  gradually 
decrease  in  length  as  they  recede  farther  and  farther  from 
the  head.  This  point  is  mentioned  to  explain  clearly  why 
no  molder  scale  can  be  reversed. 

Now,  when  the  molder  scale  is  laid  out,  as  just  described, 
it  can  be  transferred  to  a  hardwood,  metal,  or  celluloid 
gage  as  shown  in  Fig.  75,  or  it  may  be  scribed  on  either 
a  little  brass  T-square  or  the  edge  of  an  ordinary  rule.  It 
can  then  be  used  for  laying  out  new  knife  shapes  to  guide 
one  in  both  the  grinding  and  setting  operations,  see  Chapter 
I.V.,  "Setting  Up  a  Molder". 

Fig.  76  shows  a  method  of  laying  out  knife  shapes  with  a 
small  drafting  outfit.  A  full-size  head  is  laid  out  per- 
manently on  a  small  drawing  board.  The  sides  of  the  head 
are  square  with  the  edges  of  the  board,  and  knife  line  K  B 
D  is  parallel  to  the  line  of  actual  measure  C  Y  A.  The 
horizontal  base  line  X  Y  Z  intersects  veitical  line  C  Y  B 
at  right  angles  and  is  tangent  to  the  cutting  circle  of  the 
surfacing  knives.  A  tracing  of  the  full-sized  molding  is 
tacked  to  the  board  so  that  its  inside  edge  lies  on  line  Y  A 
and  its  highest  point  touches  line  X  Y,  as  shown  in  Fig. 
76.  Now,  with  the  T-square,  draw  horizontal  lines  thru 
important  parts  of  the  molding  and  let  them  intersect 
vertical  line  Y  A.  With  the  compass  centered  at  C,  extend 
these  lines  to  the  knife  projection  line  B  D.  At  points 
on  the  molding-outline  where  the  horizontal  lines  inter- 
sect, square  up  as  at  1,  2,  3,  4,  5,  etc.  Then  square  back 
across  with  T-square  from  the  intersections  on  line  B  D 
and,  where  the  vertical  and  horizontal  lines  intersect  di- 
rectly above  the  molding,  the  correct  knife  profile  can  be 
traced,  as  shown  in  Fig.  76.  This  method  of  laying  out 


128  MACHINE  MOLDER  PRACTICE. 

knives  is  accurate  but  slow,  and  therefore  only  recom- 
mended for  study  practice  and  use  in  drafting  rooms. 

Expert  knife  makers  use  neither  the  drafting  system 
nor  the  sticker  rule  for  obtaining  correct  shapes,  but  im- 
mediately begin  grinding  the  knife  to  shape  on  a  coarse, 
free-cutting  wheel  without  any  preliminaries  whatever. 
First  the  knife  is  ground  to  a  shape  exactly  the  reverse  of 
the  molding,  then  ground  deeper  to  make  allowance  for  the 
greater  knife  projection.  At  this  stage  of  the  process  one 
is  guided  by  good  judgment  and  a  practiced  eye.  As  the 
grinding  nears  completion  the  knife  is  taken  from  the 
wheel  repeatedly -and  held  over  the  drawing,  or  fitted  to  the 
sample  at  the  angle  which  it  cuts.  The  angle  is  changed  for 
deep  and  shallow  cuts  as  dictated  by  keen  judgment.  By 
sighting  down  over  the  edge  of  the  knife  to  the  outlines  of 
the  drawing  or  sample,  one  can  tell  when  the  shape  is  right, 
and  when  right,  the  clearance  bevel  is  ground.  This 
method  of  grinding  knives  to  shape  is  not  guesswork,  as 
one  might  presume,  but  is  a  matter  of  skill  and  practice, 
being  used  by  some  of  the  most  accurate  and  fastest  molder- 
men  in  the  country.  By  using  this  system,  a  rapid  work- 
man will  have  a  knife  half  completed  in  the  time  that  it 
ordinarily  takes  to  lay  out  a  knife  shape  with  pencil  and 
paper.  . 

Before  leaving  the  subject  of  knife  shapes,  it  might  be 
well  to  explain  a  little  point  over  which  there  has  been  some 
argument  and  speculation  among  moldermen.  The  question 
is,  why  a  straight  miter  or  bevel  cannot  be  cut  with  a 
straight-edged  knife.  The  fact  of  the  matter  is  that  a 
straight-edged  miter  knife  cuts  a  slightly  convex  or  curved 
miter,  while  to  produce  a  really  straight  miter  or  bevel  the 
knife  must  be  slightly  curved  (convex)  instead  of  straight. 
This  apparent  paradox  is  due  to  two  things :  the  elongation 
of  the  cutter  to  conform  to  the  elongated  molder  scale,  and 
the  fact  that  the  cutting  angle  of  the  knife  changes  ac-- 


KNIFE  MAKING.  129 

cording  to  the  depth  of  cut.    The  layout  of  a  miter  knife 
in  Fig.  77  shows  the  slight  curvature  clearly. 

Another  thing  worth  remembering  about  knife  shapes 
is  that  a  knife  ground  to  cut  a  perfect  quarter-round  or 
half-round  is  part  of  a  true  elipse.  One  method  of  laying 
out  knives  to  cut  perfect  quarter  and  half-rounds  appears 
in  Fig.  78.  A  wood- turning  of  the  proper  diameter,  how- 
ever,, is  probably  the  best  thing  to  use  in  trying  out  a 
quarter  or  half-round  knife  to  prove  its  accuracy  before 
putting  it  in  service.  Moldermen  who  have  occasion  to 
make  a  great  deal  of  round  molding  will  find  it  advan- 
tageous to  prepare  a  stick  with  different  diameter  sections 
turned  along  its  length  for  this  purpose. 

Knives  for  round  heads  can  be  drafted  and  ground  to 
shape  in  a  manner  similar  to  that  just  described  for  square . 
heads.  The  principle  is  exactly  the  same  in  both  cases. 
The  proper  bevel  for  the  edge  of  molding  knives  depends 
largely  upon  the  size  of  the  head  and  the  angle  at  which 
the  knives  cut.  There  must  always  be  more  than  enough 
bevel  for  back  clearance  in  order  to  give  an  acute  cutting 
edge  and  prevent  any  possibility  of  shavings- catching  be- 
tween the  heel  of  the  knife  and  the  finished  molding. 
Knives  for  comparatively  shallow  cuts  should  be  beveled 
on  the  edge  about  33  to  36  degrees,  while  those  for  deeper 
cuts  may  be  given  an  edge-bevel  of  40  to  45  degrees,  see 
Figs.  73  and  74.  The  reason  for  the  shorter  bevel  on  long 
knives  is  to  give  greater  strength  at  the  cutting  edge.  The 
amount  of  bevel  for  side  clearance  need  never  be  more  than 
5/16-in.  or  %-in.  to  the  inch,  or  about  %-in.  to  the  thick- 
ness of  an  ordinary  knife. 

Knives  made  of  carbon  steel  must  be  given  heat  treat- 
ment, followed  by  quenching  in  oil,  water,  or  some  liquid 
solution  to  give  them  the  proper  degree  of  hardness  or 
temper  along  the  cutting  edge.  A  knife  that  has  slender 
points  should  not  be  ground  to  finish  size  until  after  re- 
ceiving heat  treatment.  A  new  knife  edge  should  be  left 


130 


MACHINE  HOLDER  PRACTICE. 


thicker  at  all  narrow  points  and  corners  so  that  when  it  is 
being  heated  at  the  forge  these  points  will  not  be  so  likely 
to  heat  too  rapidly  and  burn  before  the  rest  of  the  knife 
becomes  red  hot.  If  the  knife  is  to  be  heated  in  an  open 
forge,  use  old  coals  or  charcoal  for  the  fire  in  preference  to 
fresh  coal  because  the  latter  may  contain  sulphur  or  other 


Fig.  77.     Layout  of  a  knife  to  cut  a  miter, 
curvature  of  knife  edge. 


Notice  the  slight 


chemical  properties  that  may  injure  the  steel.  Before  put- 
ting a  knife  into  a  forge  fire,  it  is  important  to  have  a 
heaping  bed  of  red  hot  coals.  Lay  the  knife  face  up  on  the 
hot  coals  and  concentrate  the  greatest  heat  a  little  back  of 
the  beveled  heel.  Never  heat  the  cutting  edge  first.  See 
that  the  heat  plays  uniformly  along  a  line  about  %-in.  or  so 
back  of  the  heel.  This  uniform  heating,  which  is  so  im- 
portant, is  accomplished  by  turning  and  shifting  the  knife 


KNIFE  MAKING.  131 

with  the  tongs.  Operate  the  bellows  slowly  to  give  a  quiet 
but  positive  draft  until  an  even  dark  red  appears  along  the 
entire  edge  of  the  knife  and  %-in.  or  more  back  to  the  edge. 
Heating  along  back  of  the  heel,  as  directed,  permits  the  heat 
to  spread  more  evenly  and  prevents  the  sharp  cutting  edge 
from  overheating.  If  perchance  a  slender  point  on  the  edge 
heats  too  rapidly,  withdraw  the  knife  and  cool  that  point 
either  on  cold  iron,  in  tallow,  or  oil,  then  replace  the  knife 
and  continue  heating  it.  Never  let  a  knife  lay  on  or  in  hot 
coals  to  absorb  heat,  but  try  to  keep  its  temperature  rising 
and  quench  it  at  a  rising  heat. 

As  the  knife  gradually  becomes  a  little  brighter  than  dull 
red,  push  the  entire  edge  into  the  coals,  and  then  when  it 
is  a  cherry  red  (a  shade  between  dull  and  bright  red) 
withdraw  the  knife  quickly  and  plunge  it  point  downward 
into  a  bucket  of  linseed  oil,  fish  oil,  or  some  suitable  quench- 
ing liquid,  and  stir  it  vigorously  to  cool  quickly  and  tho- 
roly.  When  the  knife  is  cool,  wipe  it  dry  and  try  the 
beveled  cutting  edge  with  a  file.  If  it  files  easily,  it  is  too 
soft.  Should  the  file  glaze  over  it  like  glass  and  not  bite, 
the  edge  is  then  too  hard  and  must  be  tempered  to  reduce  the 
degree  of  hardness.  When  the  file  takes  hold  on  the  edge 
and  bites  with  difficulty,  the  edge  is  just  right.  A  knife 
that  is  found  to  be  too  soft  after  heating  and  quenching,  as 
described  above,  has  evidently  not  been  heated  hot  enough 
or  else  not  quenched  quickly  and  thoroly  while  at  a 
rising  heat.  A  knife  that  is  a  little  too  hard  can  be  easily 
tempered.  First  brighten  the  edge  and  face  with  sand- 
paper or  some  abrasive;  heat  it  some  distance  back  from 
the  edge  on  a  red  hot  iron  or  over  the  hot  coals  in  the 
forge.  After  a  little  heating,  colors  will  begin  to  appear. 
When  a  yellow  or  straw  color  spreads  to  the  cutting  edge, 
remove  the  knife  and  cool  it.  This  usually  gives  a  good 
temper  for  wood  cutting  and  the  edge  can  barely  be 
scratched  with  a  file. 

There  are  several  different  ways  of  quenching  steel  after 


132  ,  MACHINE  HOLDER  PRACTICE. 

it  has  been  heated  to  a  cherry  red.  Often  the  method  is 
varied  somewhat  to  suit  the  kind  of  steel  or  quenching 
liquid  available.  Some  knife  makers  prefer  about  V^-in.  of 
oil  on  top  of  the  water.  They  dip  the  knife  into  the  oil 
slowly,  heel  first,  passing  it  slowly  thru  the  oil  and  into 
the  water  until  the  knife  becomes  black.  Then  it  is  quickly 
withdrawn  and  polished  on  the  edge  and  face.  Usually 
enough  heat  remains  in  the  part  held  by  the  tongs  to  temper 
the  edge.  The  colors  begin  to  appear  as  the  knife  is  held  in 
the  air,  and  when  a  yellow  spreads  to  the  edge,  the  knife 
is  cooled  in  water.  This  is  a  rapid  method  because  only 
one  heat  is  used  for  both  the  hardening  and  tempering. 

In  the  absence  of  oil,  water  is  sometimes  used  for  quench- 
ing but  is  not  recommended  because  it  may  crack  the  steel 
or  make  it  so  hard  and  brittle  that  it  will  crack  when  in 
service.  If  water  must  be  used,  the  knife  should  be  slowly 
dipped  into  it,  heel  first,  but  only  at  the  surface  however, 


Figr.  78.     One  way  to  lay  out  quarter  and  half-round  knives. 

then  withdrawn  and  dipped  again,  each  time  a  little  deeper, 
repeating  the  process  until  the  knife  is  black.  Then  polish 
quickly  and  temper  as  described. 

There  are  a  number  of  so-called  secret  solutions  for 
quenching  steel,  and  while  some  give  good  results,  they  are 
all  more  or  less  expensive  and  very  few  excel  good  linseed 


KNIFE  MAKING.  133 

oil  or  a  combination  of  fish  oil,  linseed  oil,  and  tallow. 
Plain  lubricating  oil  can  be  used  with  fairly  satisfactory 
results.  Oil  of  one  kind  or  another  is  pref  ered  to  water  on 
account  of  its  milder  action  as  a  cooling  agent. 

After  a  knife  has  been  properly  tempered  the  edge 
should  be  ground  smooth  and  sharp,  and  whetted  lightly 
with  a  whetstone.  It  is  then  ready  for  use.  To  preserve 
the  exact  shape  of  irregular  stock  knives,  patterns  to  fit  the 
cutting  edge  can  be  made  of  sheet  metal  and  filed  away 
with  either  the  knife,  the  molding  sample,  or  set-up  temp- 
lets. 

Bar  steel  for  spike  knives  is  generally  cut  into  lengths 
suitable  for  knives  by  grinding  deep  grooves  across  the  - 
side  with  a  thin  emery  wheel  and  then  breaking  off  the 
pieces  in  the  vise.  When  following  this  method,  grind  the 
grooves  on  one  side  only,  as  shown  at  A,  Fig.  79,  not  on 
both  sides  as  at  B,  Big.  79.  The  latter  is  a  very  wasteful 
practice  and  requires  considerable  more  grinding  to  attain 
the  cutting  bevel. 

The*  practice  of  heating  and  swa'ging  or  spreading  the 
cutting  end  of  spikes  by  hammering,  see  Fig.  80,  before 
they  are  ground  or  tempered  is  very  good  because  it  gives 
a  wider  cutting  edge  and  leaves  less  to  do  when  beveling 
the  edge.  It  is  also  claimed  that  hammering  hot  steel 
during  the  swaging  process  tends  to  compress  it  and  make 
the  cutting  edge  more  tough. 

Knives  for  cutting  wood  across  the  grain  are  often 
twisted  or  forged  to  a  curve  to  give  tr^e  cutting  edge  a 
shear  cut  similar  to  the  angle  of  knives  on  automatic  lathes 
and  tenoner  heads,  see  Fig.  81.  A  shear  cutting  knife  with 
a  hard  edge  produces  much  smoother  work  than  straight 
knives.  Twisted  knives  are  sometimes  used  for  making 
deep,  perpendicular  or  nearly  perpendicular  edge  cuts  with 
the  top  or  bottom  heads,  The  twist  gives  the  knife  an 
acute  cutting  angle  at  the  side,  therefore  it  cuts  easier  and 
stays  sharp  longer  than  if  it  was  flat  and  made  a  side  scrap- 


134 


MACHINE   HOLDER   PRACTICE. 


ing  cut.  Knives  should  always  be  designed  to  cut  freely, 
especially  at  the  sides,  because  if  they  scrape  or  rub  the 
wood,  the  friction  causes  them  to  heat  and  dull  rapidly.  A 
knife  will  never  burn  black  if  it  is  cutting  freely,  but  it  will 
do  so  in  a  few  minutes  if  allowed  to  rub  on  the  edge  of 
stock  or  between  two  strips  of  multiple  work. 

Holder   knives   should   always   be   arranged   orderly   in 


FIG.  81 


Fig.  79.  Correct  and  incorrect  way  to  cut  off.  bar  steel  with 
emery  wheel.  Fig.  80.  A  spike  knife,  spread  or  swaged  at  end. 
Fig.  81.  A  twisted  knife. 

clean  racks  so  that  no  time  need  be  lost  in  finding  particular 
kinds.  In  large  up-to-date  factories,  knife  racks,  grinding 
wheels,  forge,  vise,  balancing  scales,  set-up  equipment,  etc., 
are  kept  in  a  separate,  well-lighted  room  called  the  grind- 
ing room.  The  knife  making,  grinding,  balancing,  and 
selecting  of  cutters  for  several  nlolders  is  all  done  by 
an  expert  molderman.  The  machine  operators  simply  do 
the  setting  up  and  tend  to  their  machines.  In  small  plants, 
however,  the  knife  rack  is  often  purposely  placed  near  the 


KNIFE   MAKING. 


135 


molder  so  that  while  the  operator  is  feeding  the  stock  on 
one  job  of  molding,  he  can  also  be  picking  out  and  balanc- 
ing cutters  for  the  next  job.  In  some  California  factories, 
a  knife  rack  is  built  right  over  the  countershaft  of  each 
molder,  and  in  front  of  the  rack  there  is  a  narrow  work 
table  or  shelf  with  drawers  for  bolts,  waste,  and  other 
paraphanalia.  The  balance  scales  sit  on  the  shelf  ready  for 
instant  use.  While  feeding  the  molder  on  one  order,  the 
operator  selects  his  cutters  and  balances  them  for  the  next 
job.  This  is  one  of  the  little  conveniences  that  enable  the 
"speed  kings"  to  make  so  many  set-ups  a  day. 


A    three-disc    side    head    tipped    to    show    self-centering-    sleeve. 


CHAPTEE  XIV. 

BABBITTING   HIGH-SPEED   BEARINGS. 

Babbitting  the  boxes,  which  carry  high-speed  spindles,  is 
very  particular  work  and  calls  for  the  exercise  of  both 
skill  and  good  judgment.  On  some  machines  there  is  a 
brass  name-plate  bearing  the  words,  "Never  babbitt  on  a 
cutterhead  journal;  you  may  spring  it,  and  once  sprung  it 
cannot  be  permanently  repaired ;  use  a  babbitting  mandrel.*' 
This  is  good  advice  and  should  always  be  followed  when 
possible.  The  greatest  danger  in  springing  a  journal  is 
when  the  hot  metal  is  poured  directly  onto  it,  and  only  on 
one  side,  to  cast  a  half  box.  The  sudden  expansion  during 
the  time  of  pouring,  and  slow  contraction  later,  is  likely 
to  produce  a  permanent  set  or  slight  bend  in  the  journal 
which  will  cause  trouble  by  heating  and  running  badly. 

When  a  journal,  however,  is  wrapped  with  two  thick- 
nesses of  thin  paper  and  both  top  and  bottom  boxes  are 
poured  at  the  same  time,  there  is  scarcely  any  danger  of 
springing  it.  Still  there  is  an  element  of  risk  in  the  latter, 
hence  the  safest  course  is  to  always  use  a  babbitting  mandrel 
made  of  an  old  spindle,  shaft,  or  stick  of  hardwood  turned 
to  the  same  diameter  as  the  journal. 

A  mandrel  should  be  wrapped  with  two  thicknesses  of 
thin  paper  and  the  ends  pasted  down  with  mucilage  or 
photo  paste.  The  paper  enlarges  the  mandrel  just  enough 
to  take  care  of  the  shrinkage  of  babbitt  in  cooling.  Babbitt 
also  casts  more  smoothly  around  paper  than  it  does  around 
a  naked  metal  shaft.  The  mandrel  must  be  carefully  and 
jfirmly  secured  in  exactly  the  same  position  that  the  cutter- 
head  spindle  assumes  while  running.  In  other  words,  if 
one  or  both  boxes  for  a  top,  bottom,  or  profile  spindle  are 
to  be  babbitted,  the  mandrel  is  placed  level  and  square  with 
the  machine  bed.  If  only  one  box  is  being  cast,  it  must 


BABBITTING  HIGH-SPEED  BEARINGS. 


137 


line  up  with  its  mate.  When  both  are  to  be  cast,  the  man- 
drel should  always  be  placed  as  nearly  in  the  center  of  the 
boxes  as  possible.  In  adjusting  a  mandrel  for  side-head 
boxes,  set  it  plumb  with  the  machine  bed. 

It  is  generally  much  more  convenient,  when  preparing 
to  babbitt  side-head  boxes,  to  detach  the  yoke  in  which  the 
boxes  are  mounted  and  take  it  to  the  repair  room  where 
the  work  can  be  done  in  good  light  near  the  forge.  Align 
the  mandrel  parallel  with  the  planed  ways  of  the  yokes. 


END 


PLAN 


SECTION  THRU  AB 


Fig.  82.  Showing-  lower  half  of  the  b&x  prepared  for  bab- 
bitting1. S,  babbitting-  mandrel  wrapped  with  paper.  L,  L, 
liners.  W,  W,  washers  at  ends.  R,  R,  putty.  * 

Clean  out  all  old  babbitt,  especially  that  in  the  anchor 
holes  and  plug  up  any  oil  holes  or  chambers  which  may  be 
in  the  bottom  box.  Oil  holes  can  be  easily  plugged  with 
bits  of  wood  whittled  round  to  fit  them.  Oil  chambers, 
however,  should  be  packed  with  waste  and  the  opening 
covered  with  a  piece  of  belting  thick  enough  to  fit  in  snug- 
ly between  the  box  and  the  babbitting  msfndrel.  This  piece 
of  belting  backed  with  waste,  not  only  keeps  the  hot  metal 
from  running  into  the  oil  chambers  or  between  the  mouth 
of  the  chamber  and  the  mandrel,  but  also  serves  as  a  shim 
which  assists  in  centering  and  supporting  the  mandrel  in 
the  box. 

A  very  simple  and  easy  method  of  centering  and  sup- 
porting a  babbitting  mandrel  is  to  place  a  narrow  strip 


138  MACHINE  HOLDER  PRACTICE.. 

of  belting  crosswise  of  the  box,  letting  it  extend  less  than 
half  way  around  the  mandrel  to  leave  plenty  of  room  for 
melted  babbitt  to  flow  in  all  parts  of  the  box.  After  the 
box  has  been  cast,  these  strips  of  leather  ,may  either  be 
left  in  position  or  replaced  with  felt.  When  both  top  and 
bottom  boxes  require  new  babbitt  lining,  considerable  time 
can  be  saved  by  arranging  to  pour  both  boxes  at  the  same 
time.  As  in  all  cases,  the  edges  of  the  boxes  must  be 
separated  by  liners  to  provide  enough  take-up  adjustment 
for  wear.  A  plan  or  top  view  of  the  bottom  half  of  a 
bearing  ready  to  be  poured  in  the  manner  recommended 
appears  in  Fig.  82.  The  liners  L,  L  are  made  of  cardboard 
or  thin  wood  and  have  small  V-notches,  as  shown,  to  per- 
mit the  melted  babbitt  to  flow  from  the  top  half  of  the 
box  down  to  the  lower  half.  When  the  metal  cools,  it  will 
be  joined  together  at  the  V-notches,  but  these  slender  con- 
nections are  easily  broken  apart  by  a  few  taps  of  the  ham- 
mer on  the  end  of  the  top  box,  or  the  prying  action  of  a 
chisel.  If  only  the  top  half  of  the  Box  is  to  be  cast,  tho 
liners  are  not  notched  at  all. 

After  the  oil  holes  and  chambers  are  plugged  and  the 
babbitting  mandrel  is  properly  centered  and  clamped  in 
place  between  liners,  see  Fig.  82,  the  cap  (top  half  of  box) 
is  set  over  the  mandrel  and  clamped  or  bolted  down  against 
the  liners.  Leather  or  cardboard  w-ashers  W,  W,  Fig.  82, 
are  then  placed  at  each  end  and  the  end  openings  sealed 
with  putty,  clay,  dough,  or  a  mixture  of  asbestos  and  oil,  see 
E,  E,  Fig.  82.  Two  open  holes  should  be  left  in  the  top  of 
the  cap,  one  for  pouring  the  metal  and  the  other  for  a  vent 
to  permit  the  escape  of  entrapped  air.  Care  must  be  taken 
that  no  moisture  is  present  in  the  boxes  when  the  metal  is 
poured  or  a  "blow-out"  will  result  from  sudden  forma- 
tion of  steam.  If  the  work  is  done  in  a  cold  atmosphere, 
the  boxes  and  mandrels  should  be  warmed  before  the  metal 
is  poured.  This  avoids  chilling  the  hot  metal  and  permits 
the  box  to  shrink  somewhat  with  the  metal  when  both 


BABBITTING   HIGH-SPEED   BEARINGS. 


139 


cool,  thereby  preserving  a  firmer  connection  between  the 
two. 

When  everything  is  in  readiness,  the  babbitt  is  melted  in 
a  regular  ladle.  In  the  absence  of  a  proper  instrument  for 
taking  the  temperature,  one  must  simply  use  good  sense 
in  heating  the  metal,  not  too  hot,  but  hot  enough  that  it 
will  run  freely  into  all  parts  of  the  box  before  it  begins 


Fig.   83. 


Oil  channels  spread  in  direction  of  rotation  from 
supply  holes,  H,  H. 


cooling.  The  temperature  at  which  babbitt  should  be 
poured  is  about  450  to  460  degrees  C.  Pour  the  metal  in 
a  steady  stream,  being  careful  not  to  let  any  of  the  top 
islag  enter  the  box  and  be  sure  to  have  enough  metal  to  fill 
the  entire  box  with  one  pouring.  Do  not  disturb  the  newly 
cast  box  until  it  has  cooled ;  then  take  the  boxes  apart  and 
smooth  off  all  rough  or  sharp  edges  with  a  chisel  or  rasp, 
and  babbitt  scraper.  Open  the  oil  holes,  and  chambers  if 
any,  and  cut  oil  channels  from  them  to  points  near  the 
ends  of  the  box,  as  shown  in  Fig.  83.  The  function  of 
the  oil  channels  is  to  facilitate  the  flow  of  oil  to  all  parts  of 
the  bearing,  therefore,  they  should  lead  outward  from  the 
supply  holes  in  the  direction  of  rotation.  Their  edges  and 
those  of  the  boxes  should  be  rounded  because  sharp  edges 
tend  to  scrape  oil  off  the  journal  and  prevent  its  proper  dis- 
tribution. 

Every  babbitted  bearing  must  be  carefully  scraped  to  fit 


140  MACHINE  HOLDER  PRACTICE. 

its  journal  perfectly.  Otherwise,  the  journal  will  bear  only 
on  high  spots  and  all  lubricant  will  be  forced  into  the  low 
places  where  it  will  not  do  any  good.  Under  such  condi- 
tions, overheating  is  certain  to  occur,  even  tho  the  bear- 
ing is  flooded  with  oil.  In  order  to  know  where  to  scrapp, 
give  the  journal  a  very  thin  coating  of  red  lead  paint  and 
turn  it  around  in  the  boxes.  The  bright  spots  show  where 
the  surface  must  be  scraped.  When  the  fit  between  journal 
and  boxes  appears  to  be  perfect,  bolt  the  latter  in  place,  put 
on  the  belts,  and  run  the  spindle  up  to  speed  for  a  few 
minutes.  Take  the  boxes  apart  again,  and  the  bright 
places  caused  by  friction  show  exactly  where  to  do  the  light, 
final  scraping.  This  all  takes  time,  but  is  worth  it,  because 
it  produces  smooth-running,  non- troublesome  bearings 
which  are  so  essential  to  good  molder  work. 

When  adjusting  new  boxes  to  a  high-speed  journal,  do 
not  make  the  mistake  of  clamping  them  down  too  tight. 
Leave  a  little  play  at  first  and  run  the  spindle  at  full 
speed  for  a  while  to  let  it  warm  up.  The  expansion  from 


B 


Babbitt  scrapers  are  usually  made  by  grinding  a  half-round 
file  as  shown  at  C,  or  a  three- cornered  file  as  illustrated  by 
cross -section  D. 

heating  may  be  enough  to  take  up  all  lost  motion,  but  if  it 
is  not,  then  tighten  the  boxes  just  a  trifle  while  they  are 
warm. 

In  babbitting  a  box  which  receives  a  grooved  journal 
(grooved  to  prevent  side  play  in  the  spindle)  the  usual 
practice  is  to  give  the  journal  a  good  coat  of  white  lead 
paint,  and  then  use  it  as  a  mandrel  for  molding  the  babbitt 
lining.  A  wood  mandrel  with  corresponding  grooves  can 
be  turned  by  an  expert  turner  if  a  templet  is  provided,  to 


BABBITTING  HIGH-SPEED  BEARINGS.  141 

fit  accurately  into  the  grooves.  The  wood  mandrel  is  rec- 
ommended because,  if  a  grooved  journal  is  sprung  the  least 
bit,  it  is  practically  ruined  foreven 

The  lubrication  of  high-speed  bearings  is  of  great  im- 
portance. To  run  properly,  a  journal  and  its  bearings  must 
always  be  separated  by  a  thin  film  of  oil.  It  is  quite  im- 
perative that  good  oil  be  used  and  the  supply  be  kept  con- 
stant in  order  to  maintain  perfect  lubrication.  It  is  often 
necessary,  especially  on  large  bearings,  to  introduce  oil  from 
the  bottom  as  well  as  the  top.  If  there  is  no  provision  for 
an  underfeed  oil  system,  and  one  is  desired,  drill  a  small 
hole  through  the  bottom  of  the  box  and  tap  it  for  a  small 
U-shaped  pipe.  The  short  leg  of  the  U  should  then  be 
screwed  into  the  bottom  casting  and  the  long  leg  fitted 
with  a  sight  feed  or  plain  metal  oil  cup.  Oil  channels 
must  then  be  cut  in  the  bottom  box  the  same  as  in  the  cap. 


CHAPTEE  XV. 

BELTING  AND  INSTALLING  HOLDERS. 

Leather  belting  of  good  quality  is  undoubtedly  the  best 
for  driving  molder  cutterheads.  Light  (22  or  24-oz.)  two- 
ply  belting  is  generally  the  correct  selection  for  heavy-duty 
top  and  bottom  head  drives,  but  single-ply  center  stock  is 
the  logical  choice  for  side  head  and  all  other  drives  on 
medium  and  small  size  machines.  Next  to  leather  is  the 
four  and  five-ply  woven  canvas,  impregnated  with  rubber  or 
a  similar  substance. 

.  To  drive  a  cutterhead  effectively,  the  belt  must  be  very 
flexible  so  it  will  wrap  around  the  small  pulleys  to  good 
advantage.  It  must  have  great  strength  and  be  able  to 
stand  up  under  continuous  high-speed  service.  When  tight- 
eners are  brought  to  bear  on  belts  to  keep  them  at  uniform 
tension,  as  they  gradually  become  lengthened  from  con- 
tinued service,  the  belts  should  be  made  endless.  Other- 
wise, the  ends  are  usually  joined  together  with  a  tough  wire 
lacing  either  hand  or  machine  sewed.  When  cutting  a  new 
belt  to  net  length,  it  is  usually  safe  to  allow  about  1/10-in. 
to  %-in.  to  the  lineal  foot  for  stretch.  In  other  words,  cut 
it  just  that  much  shorter  than  the  actual  tape  measurement 
around  the  pulleys.  Cut  the  ends  of  the  belt  perfectly 
square  with  a  try-square.  For  ordinary  wire  lacing,  to  be 
put  in  by  hand,  use  a  punch  which  cuts  a  hole  slightly  less 
than  Vs-in.  Punch  a  single  row  of  holes  5/16-in.  from  the 
end  and  let  the  holes  be  about  %-in.  apart  on  center.  Make 
an  even  number  of  holes  in  each  end,  if  possible,  so  the 
belt  can  be  sewed  in  such  a  manner  as  to  equalize  the  side 
pull  of  cross-over  strands  at  each  side  of  the  center,  see 
Fig.  84. 

The  method  of  sewing,  shown  in  Fig.  84,  is  simple  but 
effective  and  keeps  the  edges  of  the  ends  even.  Always 


BELTING  AND  INSTALLING  HOLDERS. 


143 


turn  the  grain  or  smooth  side  of  a  single-ply  belt  to  the 
pulley  and  lace  so  that  no  cross-over  strands  show  on  the 
pulley  side.  Cut  the  wire  about  seven  times  longer  than  the 
width  of  the  belt  and  start  the  two  ends  from  the  back 
side  of  the  belt  throught  holes  1  and  1-A,  respectively.  Pull 


Fig.  84.     Method  of  sewing-  wire  lace  by  hand. 

the  ends  evenly  and  draw  them  across  the  joint  on  the  pul- 
ley side  and  thru  holes  2  and  2 -A,  respectively,  then  thru 
1  and  1-A  again,  then  cross  the  pulley  side  thru  2  and  2-A. 
One  strand  is  then  crossed  over  from  2  to  3  on  the  back 
and  the  other  over  to  3-A  from  2-A.  Continue  until  the 
edges  of  the  belt  are  reached,  and  then  cross  the  wire  over 
to  an  adjacent  hole  or  draw  it  thru  an  extra  hole,  as  shown 
at  9,  Fig.  84.  After  lacing,  hammer  the  wire  down  flat. 
The  belt  is  then  ready  for  service.  Put  single  belts  on  so 


144  MACHINE  MOLDER  PRACTICE. 

the  point  of  the  lap  on  the  inside  runs  toward  the  pulleys, 
because  the  lap  on  the  outside  of  a  belt  is  most  likely  to 
come  apart  when  the  point  is  run  against  atmospheric  pres- 
sure. Double  belts  should  be  put  on  so  the  points  of  the 
laps  will  run  with  the  pulleys  as  both  sides  point  in  the 
same  direction,  see  Fig.  85. 

Belts  should  be  kept  clean  and  free  from  oil  and  grease. 
Mineral  oils,  in  particular,  rot  leather  rapidly.  Where 
belting  is  liable  to  become  oil  soaked,  mechanical  means 
should  be  taken  to  keep  the  oil  from  the  belt.  Where  this 
is  impossible  the  belt  should  always  be  removed  from  time 
to  time  and  all  oil  extracted  by  some  solvent  such  as  naptha 
or  benzine.  Packing  the  belt  in  dry  sawdust,  whiting,  or 
some  similar  absorbent  material  will  sometimes  answer  the 
purpose.  If  it  is  impossible  to  remove  the  belt,  wiping  it 
while  on  the  pulley  with  a  dry  cloth  or  waste  will  help.  An 
excess  amount  of  oil  on  a  belt  gives  a  bad  frictional  sur- 
face and  causes  it  to  slip,  and  also  has  a  tendency  to  injure 
the  sticking  qualities  of  the  ordinary  cements  in  belt  laps. 

Should  laps  begin  to  open  up  on  account  of  the  presence 
of  oil,  it  will  be  necessary  to  de-grease  the  parts  to  be  joined 
and  scrape  off  all  old  cement,  or  the  new  cement  will  not 
stick  satisfactory.  Do  not  think  that  you  can  remedy  the 
trouble  by  riveting  or  driving  tacks  or  belt  fasteners 
through  the  joint.  This  simply  makes  a  bad  situation 
worse,  for  the  leather  will  probably  break  where  the  metal 
pierces  it.  There  is  a  right  and  a  wrong  way  to  repair 
laps,  as  well  as  to  cement  new  laps,  and  the  quickest  and 
easiest  way  is  not  always  the  most  economical  in  the  end. 
It  is  easy  to  drive  rivets  or  fasteners  in  a  belt  but  it  is 
just  as  well,  before  doing  so,  to  think  how  much  you 
weaken  the  belt  at  that  point,  how  out  of  balance  you  make 
it,  and  consequently  how  it  will  jump  every  time  the  fast- 
eners go  around  the  cutterhead  pulley.  The  proper  way 
is  to  clean  the  open  laps  and  apply  good  cabinetmaker's 
glue  or  regular  belt  cement,  rub  out  all  surplus  glue,  and 


BELTING  AND  INSTALLING  HOLDERS.  145 

then  put  on  the  clamps  or  nail  a  piece  of  board  over  the 
joint  and  let  it  stand  at  least  an  hour  before  releasing  the 
pressure. 

To  make  a  new  lap  joint  in  a  single-ply  leather  belt, 
square  the  ends  and  lay  off  the  length  of  lap  equal  to  about 
the  width  of  the  belt.  Make  the  lap  joint  point  the  same 
way  as  other  lap  joints  in  the  belt.  Work  each  lap  to  a 
feather  edge  with  a  belt  or  spoke  shave  and  scraper.  Both 


Fig.  85.     Showing  how  the  laps  in   single  and  double-ply  belts 
should  run. 

laps  must  be  made  square  and  even  so  the  joint  will  be 
the  same  thickness  as  the  rest  of  the  belt.  Eough  the  sur- 
face of  each  lap  with  a  rasp  or  piece  of  coarse  sandpaper 
to  give  the  cement  a  better  chance  to  stick.  Clamp  or 
nail  the  belt  to  a  smooth  board  so  that  if  will  lay  perfectly 
straight  when  the  laps  match  one  above  the  other.  If  the 
work  is  being  done  in  a  cold  room,  warm  the  board  and 
belt  laps  before  applying  glue  or  cement.  When  belt  cement 
is  used,  follow  the  directions  accompanying  it,  but  in  using 
cabinetmaker's  glue,  brush  it  on  both  laps  and  rub  it  in, 
then  fold  laps  together  and  rub  the  outside  of  the  joint 
briskly  with  some  blunt  tool  to  drive  out  all  air  bubbles  and 


146  MACHINE  HOLDER  PRACTICE. 

pockets.  Then  apply  a  flat  even  pressure  by  clamping  or 
nailing  a  piece  of  board  directly  over  the  joint.  Let  stand 
over  night,  or  half  a  day  if  possible,  before  releasing  the 
pressure  and  putting  the  belt  in  service. 

Avoid  putting  belts  on  too  tight.  If  a  belt  is  put  on 
and  run  too  tight,  it  becomes  overstrained  and  injured, 
excessive  friction  is  produced  in  the  bearings  and  there  is 
danger  of  damaging  the  machine  boxes.  If  the  demands 
on  a  belt  are  unusually  severe,  owing  to  a  regular  line  of 
heavy  work,  a  "floating"  tightener  can  be  placed  on  the 
slack  side  near  the  drive  pulley.  A  yielding  tightener,  de- 
riving its  tension  from  its  own  weight  or  from  coil  springs, 
is  a  good  thing,  but  when  an  unyielding  tightener  is  used 
there  is  always  a  temptation  on  the  part  of  the  operator 
to  screw  it  down  too  far  and  thereby  make  the  belt  al- 
together too  tight.  Lubricating  oil,  water,  fine  sawdust, 
and  all  general  foreign  substances  should  be  kept  off  of 
cutterhead  belts.  Keep  the  belts  clean  but  do  not  allow 
them  to  become  dry  and  hard  from  want  of  proper  lubri- 
cation. Leather  belts  in  particular  must  be  kept  pliable 
and  soft.  An  occasional  but  very  light  application  of  warm 
tallow,  neatsfoot  oil,  or  good  belt  dressing  is  just  the  thing 
to  lubricate  leather  belts.  The  practice  of  doping  a  belt 
with  rosin,  soap,  varnish,  etc.,  to  make  it  pull  better  is 
only  a  temporary  relief  and  if  continued  to  any  extent 
will  certainly  ruin  the  best  belt  ever  made.  It  is  like  dop- 
ing the  human  body  or  mind  to  produce  greater  activity. 
The  effects  of  a  treatment  soon  wear  off,  leaving  one  in 
worse  condition  than  before.  If  the  stimulation  is  con- 
tinued a  collapse  is  inevitable. 

It  is  a  good  plan  in  factories  and  mills  where  fast-feed 
machines  are  kept  in  continuous  service,  to  have  duplicate 
machine  belts  cut  to  length  and  ready  for  instant  replace- 
ment. Belts  should  be  inspected  regularly  and  given 
proper  care  and  attention,  rather  than  be  allowed  to  run  on 


BELTING  AND   INSTALLING   MOLDERS.  147 

and  on  until  they  get  in  such  a  condition  that  some  ex- 
treme action  is  necessary  to  save  them  from  ruin. 

Never  throw  a  cutterhead  belt  off  or  on  the  pulleys  at 
full  speed;  roll  it  on  by  hand  or  thrt>w  it  on  at  very  slow 
speed.  When  a  belt  is  thrown  onto  a  pulley  moving  at  high 
speed,  one  edge  of  the  belt  is  given  a  terrific  strain  all  in 
an  instant,  and  as  a  result  that  edge  is  stretched  more  than 
than  the  other.  Often  the  belt  becomes  permanently  set 
in  this  unequally-stretched  condition  and  runs  crooked  ever 
after.  Instead  of  traveling  straight,  the  crooked  belt  oc- 
cilates  across  the  faces  of  the  pulleys  and  is  likely  to  set 
up  end  play  in  the  cutterhead  spindles. 

A  belt  should  be  about  1-in.  narrower  than  the  pulleys 
over  which  it  travels.  If  it  does  not  seem  wide  enough  to 
deliver  the  power  required,  put  on  a  wider  belt  and  use 
wider  pulleys.  A  means  sometimes  employed  to  prevent 
slippage  is  to  cover  the  pulley  faces  with  leather.  It  is 
claimed  that  leather-covered  pulleys  will  enable  belting  to 
transmit  25  per  cent,  more  power  than  pulleys  having  a 
smooth  iron  surface.  In  preparing  a  pulley  for  a  leather 
covering,  begin  by  cleaning  the  surface  thoroughly*  with 
naptha  or  benzine,  then  wipe  it  dry  and  warm  it  slightly. 
If  possible,  make  the  covering  endless  and  about  %-in.  to 
the  foot  shorter  than  the  circumferance  of  the  pulley.  Place 
the  endless  cover  on  the  pulley,  pushing  it  on  about  1-in. 
or  more,  then  brush  cement  on  the  exposed  inside  surface 
of  the  cover  and  the  exposed  outside  surface  of  the  pulley, 
being  sure  that  the  cement  is  of  the  right  Consistency.  Hub 
it  thoroly  into  the  leather  and  onto  the  pulley.  Then 
take  the  pulley  by  its  spokes  and  drive  the  cover  on  by 
striking  it  on  the  floor  or  bench.  Do  this  quickly,  but  care- 
fully, for  if  you  strike  too  hard,  or  on  one  side  more  than 
the  other,  you  may  bend  the  leather  so  that  it  will  be  im- 
possible to  drive  it  onto  the  pulley.  If  it  sticks  a  little, 
pry  it  loose  with  a  screw-driver,  then  force  it  down,  using 
the  screwdriver  as  a  lever.  When  the  cover  is  completely 


148  MACHINE  HOLDER  PRACTICE. 

on,  rub  the  edges  with  some  blunt  tool  to  make  good  contact 
and  work  out  surplus  cement  and  any  air  pockets.  A  few 
livets  are  generally  added  as  a  matter  of  safety. 

To  find  the  surface  speed  of  a  belt,  multiply  the  diam- 
eter of  a  pulley  over  which  it  runs  by  3.1416  or  3  1/7,  and 
this  product  by  the  r.p.m.  of  said  pulley.  The  surface 
speed  of  a  belt  should  never  exceed  5,000-ft.  per  minute. 
The  speed  of  pulleys  or  any  rotating  parts  can  be  easily 
and  quickly  figured  if  one  remembers  this  simple  fact: 
That  the  speed  of  the  driving  pulley  in  r.p.m.  times  its 
diameter  equals  the  speed  of  the  driven  pulley  in  r.p.m. 
times  its  (the  driven  pulley)  diameter.  Example: 

Speed  of  lineshaft 300  r.p.m. 

Diameter  of  lineshaft  pulley.  .  .  30-in. 
Diameter  of  driven  pulley. . .  .  10-in. 
Speed  of  driven  pulley N 

300  x  30  =  10  x  N" 
9000  =  10  x  N 
9000 

_  =  1ST  or  900 
10 
300  x  30  =  10  x  900 

Note:     N  represents  unknown  quantity. 

A  single-ply  leather  belt,  1-in.  wide,  running  800-ft.  per  minute 
will  transmit  1  h.  p.  and  for  other  thicknesses  figure  the  unit  speed 
as  500,  40*0,  and  300,  respectively,  for  two-ply,  three-ply  and  four- 
ply.  Remember,  the  greater  the  speed  of  the  belt,  the  more  horse 
power  transmitted  in  direct  proportion,  but  do  rot  let  the  speed 
exceed  a  mile  a  minute. 

To  figure  the  length  of  belt  for  a  drive  when  it  is  incon- 
venient to  measure  the  distance  with  a  tape  line :  Add  the 
diameter  of  the  two  pulleys,  multiply  this  result  by  3.1416, 
and  divide  by  2.  To  this  quotient,  add  twice  the  dis- 
tance between  centers  of  shafts  and  this  will  give  the  re- 
quired length  provided  both  pulleys  are  about  the  same 
size.  When  one  pulley  is  considerably  larger  than  the 


BELTING  AND   INSTALLING  HOLDERS.  149 

other,  square  the  distance  between  the  centers  of  the  shafts ; 
add  to  this  the  square  of  the  difference  between  the  radii  of 
the  two  pulleys ;  from  this  total  extract  the  square  root  and 
multiply  by  two.  Call  the  total  thus  obtained,  T.  Then 
add  the  diameters  of  the  two  pulleys  together,  multiply 
result  by  3.1416  and  to  one-half  of  this  add  the  amount 
just  designated  as  T,  and  you  will  have  the  length  of  belt 
required.  To  find  the  number  of  lineal  feet  in  a  roll  of 
belting  of  any  kind  or  ply,  add  the  diameter  of  the  roll 
in  inches  to  the  diameter  of  the  center  hole,  multiply  by 
the  number  of  coils,  counting  from  the  center  to  the  out- 
side, and  multiply  this  product  by  .1309. 

SETTING  A  MOLDER. 

A  molder,  like  an  engine  or  other  important  piece  of 
machinery,  should  set  level  and  be  firmly  bolted  down  to  a 
solid  floor  or  foundation.  Concrete  foundations  are  good 
and  unless  there  is  a  good  concrete  or  heavy  plank  and 
timber  floor,  a  special  foundation  should  be  prepared.  The 
conventional  method  of  bolting  a  machine  to  a  plank  floor 
or  timber  foundation  is  to  use  lag  screws  and  washers. 
Lag  screws  are  also  used  to  anchor  machine  bases  on  con- 
crete floors  and  foundations.  Holes  are  cut  in  the  concrete 
to  correspond,  in  position,  to  holes  in  the  machine  base. 
The  machine  is  then  positioned  over  the  holes,  lined  up 
with  the  driving  shaft,  if  belt  drive  is  to  be  used,  and 
leveled  with  hardwood  shims  so  all  feet  rest  firmly  on  the 
foundation.  Small  channels  are  then  cut  to  each  hole  in 
the  concrete  and  when  the  lag  screws  are  hung  in  place 
in  the  machine-base  holes,  melted  babbitt  or  lead  is  poured 
in  around  them.  This  anchors  the  machine  very  substan- 
tially. 

Common  sulphur  is  sometimes  used  in  the  place  of  bab- 
bitt metal  because  of  its  comparative  cheapness.  When  sul- 
phur is  used,  no  channels  need  be  cut  for  pouring  because 
the  melted  sulphur  can  be  poured  directly  into  the  holes 


150  MACHINE  MOLDER  PRACTICE. 

and  the  lag  screws  set  in  immediately  after.  This  is  possible 
because  sulphur  cools  more  slowly  than  metal.  Of  course, 
the  lag  screw  is  not  pushed  all  the  way  down  in  the  cool- 
ing sulphur,  but  within  about  %-in.  or  1-in.  of  its  limit, 
and  turned  the  balance  of  the  distance  with  a  wrench. 
When  the  sulphur  hardens  it  holds  the  lag  screws  firmly 
in  place. 

Another  method  of  fastening  machines  to  concrete  foun- 
dations is  to  put  down  inverted  anchor  bolts  with  large 
washers  (washers  which  prevent  bolts  from  turning)  and 
fill  in  around  these  bolts  with  cement,  sulphur,  or  melted 
metal.  The  machine  base  is  then  set  down  over  the  pro- 
jecting ends  of  these  bolts  and  fastened  down  with  nuts 
and  washers. 

If  a  molder  is  to  be  driven  by  an  individual  motor,  the 
usual  practice  is  to  connect  the  motor  directly  to  the  ma- 
chine countershaft  by  a  flexible  coupling.  A  flexible  coup- 
ling is  preferred  to  a  solid  coupling  for  several  reasons; 
it  relieves  the  motor  of  certain  mechanical  jarring  and  aids 
it  in  getting  under  way  to  better  advantage  when  started ; 
also  permits  of  a  slight  misalignment  in  the  shafts  without 
causing  the  usual  trouble  incident  to  using  solid  couplings. 

The  size  motor  required  to  drive  any  particular  size 
molder  depends  largely  upon  the  kind  of  service  the  ma- 
chine is  to  be  put  to,  whether  light,  medium,  or  heavy  use, 
intermittent  or  continuous,  slow-feed  or  fast-feed  service, 
etc.  The  following  table  shows  pretty  nearly  the  size 
motors  required  for  various  molders  operated  under  aver- 
age conditions. 

Size  of  the  Light  and  Heavy  Service,  Fast 

Molder  Medium  Service  Feeds,  or  Both 

6-in.              5  h.p.  motor  7^  to  10  h.p.  motor 

8-in.              71/2  h.p.  motor  1.0       to  15  h.p.  motor 

10-in.  10  h.p.  motor  .  15       to  20  h.p.  motor 

12-in.  15  h.p.  motor  20       to  30  h.p.  motor 

15-in.  20  h.p.  motor  25       to  30  h.p.  motor 

18-in.  20  h.p.  motor  25       to  35  h.p.  motor 


CHAPTER  XVI. 

MOLDING  SHAPES. 


OGEE 


REVERSE  OGEE  PGEE 


ROUND  EDGE  (R.  E.)  BEAD 


COVE 


THUMB 


COVE  AND  BEAD  BEAD  AND  COVE  RABBETT 


GROOVE 


BEVEL 


ROUND  QUARTER  ROUND     fc  ROUND 


ROPE  MOLDING 


EGG  AND  DART 
(EMBOSSED) 


Names  of  a  few  common  molding  shapes. 


152 


MACHINE  HOLDER  PRACTICE. 


DOOR  SADDLE  CASKET  BAND  OR       ELECTRICAL  MOLDING 

LEDGE  (FOR  WIRES) 

MOLDING 


WINDOW  STOOL 


WATER  TABLE   OR  DRIP  CAP 


BED  MOLDING 


RABBETTED  DOOR  JAMB 


PEW  BACK  RAIL 


BRICK  MOLDING 


RABBETTED 

WAINSCOT  CAP 


Showing  one  style  each  of  several  different  kinds  of  mold- 
ing commonly  used  in  the  building  trades  and  casket  manu- 
facturing. 


MOLDING  SHAPES. 


153 


DOOR  AND  WINDOW  STOP 


CHANEL  CASING 


BACK  BAND 


THRESHOLD 


CASING  BACKED  OUT  ON  BOTTOM  TO  FIT  ROUGH  WALLS 


WJNDOW  JAMB  OR.  PULLEY  STILE 


BASE 
SHOE. 


CASKET  LID  OR 
CAP  MOLDING 


WINDOW  SILL 


154 


MACHINE  HOLDER  PRACTICE. 


OGEE  SOLID  WOOD  GUTTER 


MOLDING  SHAPES. 


155 


TWO  LAP  RUSTIC  OR    NOVELTY  SIDING 


BOSTON  CEILING 


ANGLE  RUSTIC 


NOVELTY 


The  above  patterns  are  generally  run  on  fast-feed  molders 
or  matchers,  the  Vs,  beads  and  bevels  being  worked  with  pro- 
file discs  mounted  on  the  profile  spindle.  They  can  also  be 
made  with  ordinary  knives  on  four-side,  square-head  molders. 


156 


MACHINE  MOLDER  PRACTICE. 


MACHINE   HOLDER   PRACTICE. 


157 


\ 


•8! 


o'gJi     •> 
8$" 


-S  >• 


ill 


INDEX  TO  ILLTJSTKATIONS. 


CHAPTER  1. 

Typical  outside  molder 8 

An  inside   molder 11 

Fig.  1.  Plan  and  side-view  of  molder  in  proper  align- 
ment    10 

A  square  slotted  cutterhead  fitted  with  ordinary  straight 
surfacing  knives  14 

CHAPTER  II. 

Fig.  2.     Solid    and    sectional    knives 16 

Fig.  3.     Patterns  with  thin  edges  worked  with  top  head  17 
Fig.  4.     Showing    how    sectional    cutters    should    be    ar- 
ranged      19 

Fig.  5.     A  few  different  types  of  knives 21 

CHAPTER  III. 

Fig.  6.     Balancing  knives  set  in  staggered  fashion 24 

Thin  high-speed  steel  knives  attached  to  square  head, 
with  caps  and  bolts 26 

CHAPTER  IV. 

How  to  use  the  molder  or  "stickerman's"  rule..     29 
Another  method  of  setting  knives  correctly 33 

CHAPTER  V. 

Figs.  9,  10,  11,  12,  13,  14,  15.  Moldings  on  which  under- 
cutting is  necessary 37 

Fig.  16.  Attachment  for  working  Byrkit  lath,  at  rear 
end  of  an  inside  molder 39 

A  square  self-centering  side  head  fitted  with  thin  knives 
and  caps  ,  , . , ,  54 


INDEX  TO  ILLUSTRATIONS.  159 

CHAPTER  VI. 

Figs.  17  and  18.    Making  half-round  bushings,  for  pulleys  42 

Fig.  19.     Trough  in  which  piano  fall  boards  are  run 43 

Fig.  20.     Cross-section  of  a  front  fall  board 44 

Fig.  21.     Special  machine  for  tapering  and  jointing  col- 
umn staves  in  one  operation. 46 

Fig.  22.     One  method  of  making  plain  tapered  staves  in 

one  operation    47 

Fig.  23.     Showing  how   staves   for  tapered   columns  are 

laid  out  48 

Fig.  24.     Stave  in  position  alongside  form 49 

Fig.  25.     Method   of   laying   out   sprung   crown   molding 

for  circular  porches  or  1  owers 50 

Fig.  26.     Arrangement  of  guides  for  running  circle  work  52 

Fig.  27.     Molding  segment  and  circle  work  on  edge 53 

CHAPTER  VII. 

Figs.  28  and  29.     Arrangement  of  knives  and  guides  for 
running  molding  face  down 56 

CHAPTER  VIII. 

Fig.  30.     Three  methods  of  fitting  up  knives  for  planing 

without  tearing  cross-grain .. 60 

Fig.  31.  Another  way  to  fit  up  surfacing  knives  for 

working  cross-grain 61 

Figs.  32  and  33.  Methods  of  fitting  up  rabbetting  knives 

to  make  non-tearing  cut 62 

Figs.  34  and  35.  Special  knives  for  cutting  the  edge  of 

rabbetts 63 

Fig.  36.  Special  grooving  cutter 64 

Fig.  37.  Reinforcing  a  wide  knife 66 

Fig.  38.  Four  different  kinds  of  side  braces 67 

Fig.  39.  Two  ways  to  brace  extra  long  knives. .  ; 68 

Fig.  40.  Four  types  of  "scoop"  knives  for  making  gutter  69 

Fig.  41.  Bracing  a  loop  knife  with  T-bolt  and  steel  block  70 
Fig.  42.  Another  method  of  clamping  loop  knives  to  a 

square  cutterhead    71 


160  MACHINE  HOLDER  PRACTICE. 

Fig.  43.     Making  ogee  gutter 72 

Fig.  44.     Special  blocks  for  enlarging  square  heads 73 

Fig.  45.     Hooks   in   position   to   hold   projecting   ends   of 

long  knives    74 

CHAPTER  X. 

Fig.  46.     Making  moldings   in   pairs,   face   down 76 

Fig.  47.     Center  guide  in  pressure  bar 77 

Fig.  48.     Picture  frame  moldings  made  in  pairs,  face  up     78 

Fig.  49.     Four  types  of  practical  splitting  cutters 80 

Fig.  50.     Special    high-speed    steel    splitting    cutter    and 

holder 81 

Fig.  51.     Saving  an  extra  molding  by  under-cutting 82 

F'ig.  52.     Combination    head   for   splitting   and   planing..     83 
Fig.  53.     One  method  of  making  screen  door  stock  and 

saving   the    molding.      Fig.    54.      Machine    set    up    for 

making  molding  in  Fig.  53 84 

Gang  of  splitting  saws  mounted  on  self-centering  sleeve 

for  use   on  molder   spindle 85 

CHAPTER  XI. 

Fig.  55.  Divided  rip  saw  for  use  on  top  or  bottom 
spindles  86 

Fig.  56.  Position  of  top  rolls  for  feeding  special  casket 
sides  87 

Fig.  57.  lyine-up  of  guide  rail  and  inside  head  for  mak- 
ing slack-center  glue  joints 88 

Fig.  58.     Method  of  making  stair  rail  in  two  runs 90 

Fig.  59.     Special  head  rabbetted  to  receive  formed  lips..      92 

CHAPTER  XII. 

An  outside,  four-head,  fast-feed  molder 94 

One    type    of   six-knife,    slip-on    round    head    for    top    or 

bottom   spindle    of   molder    . .  . .' 95 

Self-centering  "vise-grip"  profile  head 96 

Two  universal  chamfer  heads 97 

A  fast-feed  molder  with  hopper  feed 98 


INDEX  TO  ILLUSTRATIONS.  161 

A    three-disc,     combination     head     for     grooving-     heavy 

planks,  etc 99 

Special  combination  head  used  by  N.  C.  R.  Go 101 

A  five-head  molder 102 

Profile  beader  head  fitted  with  high-speed  steel,  formed 

knives  103 

A  groove  head  for  flooring 104 

Fig.  60.  Transverse  T-slot  head  carrying  formed  knives 

for  multiple  work 105 

Fig.  61.  Knife  setting  jig  for  round  heads 106 

Fig.  62.  Radial  gage  for  setting  knives  107 

Fig.  63.  A  stand  for  setting  and  balancing  irregular 

cutters  108 

Fig.  64.  Jointing  straight  thin  steel  knives  on  a  round 

head  109 

Fig.  65.  Jointing  thick  knives  on  square  head 110 

Grinding  straight  knives  with  portable  grinder  Ill 

Fig.  66.  One  type  of  side  head  truing  device  in  posi- 
tion ..  , 112 

Fig.  67.  Formed  stone  and  holder  for  jointing  irregu- 
lar knives  on  top  or  bottom  head 113 

Fig.  68.  Another  type  of  side-head  jointer  and  special 
four-wing,  fast-feed  head  fitted  with  self-centering 
sleeve  and  thick  high-speed  steel  cutters 114 

Fig.  69.  Side  head  jointing  attachment  in  position  for 
jointing  the  formed  cutters  of  a  matcher  head 115 

Fig.  70.  Showing  one  type  of  jointing  device  attached 
to  slide  bar  on  a  jointing  and  setting  stand 116 

A  two-disc  combination  of  self-centering  clamp  sleeve.  .    117 

One   type   of   pedestal   head   grinder 118 

A   six-head,   fast-feed,    inside   molder    120 

Inserted  tooth  rip  saw  with  clamp  collar  and  self-cen- 
tering sleeve  121 

CHAPTER  XIII. 

Figs.  71  and  72.  Two  different  methods  of  making  rab- 
betted  molding  124 


162  MACHINE  HOLDER  PRACTICE. 

Figs.   73,   74,   75.     Showing  how  cutting  angle   changes 

with  depth  of  cut,  and  how  to  lay  out  molder  scale..    126 
Fig.  76.     Laying  out  knife  profile  with   drawing  instru- 
ments       129 

Fig.  77.     Layout  of  knife  to  cut  a  perfect  miter 130 

Fig.  78.     Laying   out   quarter-round   knives 132 

Figs.   79,   80,   81.     How   to   cut,   spread   and   twist   spike 

knives    134 

A    three-disc    side    head    tipped    to    show    self-centering 
sleeve    135 

CHAPTER  XIV. 

Fig.  82.     Showing  lower  half  of  cutterhead  box  prepared 

for  babbitting    137 

Fig.  83.     Proper   location    of   oil    channels 139 

A  handy  babbitt  scraper 140 

CHAPTER  XV. 

Fig.  84.     Method  of  sewing  belt  with  wire  lace 143 

Fig.  85.     Showing    how    laps    in    single    and    double-ply 
belts  should   run    145 

CHAPTER   XVI. 

Molding  shapes  and  patterns 151,  152,  153,  154,  155 

A  general  purpose  outside  molder  built  to  take   slip-on 

heads    156 

An  all  motor-driven,  ball-bearing  molder 157 


MACHINE   MOLDER  PRACTICE.  163 


REPRESENTATIVE  TYPES 

OF  MODERN 
MOLDING  MACHINES 

D   D 
D 


MACHINE  MOLDER  PRACTICE. 


MACHINE    HOLDER   PRACTICE. 


PATENTED  

E  A.GLESFI  ELD 
MOULDER 

COMPLETELY  MOTOR  DRIVEN 

SPECIFICATIONS 

SIX-INCH  MOULDER. 

Diameter  of   Spindles,   where   heads   slip   on 1-13/16-in. 

Diameter  of  Cutter  Heads 4  to  7-in. 

Type  of  Cutter  Heads Slip-on,  Round  or  Square 

Spindle  Speeds  3,450  to  3,600-r.p.m. 

Vertical  Spindles   (length  for  head) 4-in. 

Vertical  Spindles,   maximum  angle    45-deg. 

Number  of  Feed  Speeds 4 

Standard  Feeds   25  to  100-f t.  per  min. 

Diameter  of  Feed  Rolls 8-in. 

Width  of  Stock 00  to  6-in. 

Thickness  of  Stock 00  to  4-in. 

Current 110,  220,  440,  550  Volt,  2  or  3  Phase,  60  Cycles 

Table  Height    34-in. 

Length  over  all    88-in. 

Width  over  all    46-in. 

Approximate   Weight    6,800-lbs. 

TWELVE-INCH   MOULDER. 

Diameter  of  Spindles,   where  heads  slip  on 1-13/16-in. 

Diameter  of  Cutter  Heads 4  to  7-in. 

Type  of  Cutter  Heads Slip-on,  Round  or  Square 

Spindle  Speeds   . 3,450  to  3,600-r.p.m. 

Vertical  Spindles    (length  for  head) 4-in. 

Vertical  Spindles,   maximum  angle    45-deg. 

Number  of  Feed  Speeds    4 

Standard  Feeds   25  to  100-ft.  per  min. 

Diameter  of  Feed  Rolls  8-in. 

Width  of  Stock 00  to  12-in 

Thickness   of   Stock 00  to    4-in. 

Current 110,  220,  440,  550  Volt,  2.or  3  Phase,  60  Cycles 

Table  Height   34-in. 

Length  over  all   96-in. 

Width   over  all    48-in. 

Approximate   Weight    8,000-lbs. 

EXTRA  ATTACHMENTS. 

Hopper  Feed  Attachment  to  Take 3  or  6-ft.  Lengths 

Jointers  for  Top,  Bottom  and  Side  Heads. 
Knife  Grinder,  motor  driven. 
Shaving  Hoods. 

VONNEGUT  MACHINERY  COMPANY 

INDIANAPOLIS,  U.  S.  A. 


166 


MACHINE  HOLDER  PRACTICE. 


cti 

PQ 


MACHINE  HOLDER  PRACTICE.  167 

The  Mattison 

Motor  Driven 
Ball  Bearing 
Heavy  Duty 

Moulder 


Made  in  4,  6,  8,  10  and 
12-in.  Sizes 


Manufactured  by 

MATTISON  MACHINE  WORKS 

Main  Office  and  Works 
ROCKFORD,  ILLINOIS 


168 


MACHINE  MOLDER  PRACTICE. 


C 
03 

O 


MACHINE   HOLDER   PRACTICE.  169 


HERMANCE  MOLDERS 

Equipped  either  for  general 
purpose   or   fast-feed   work. 


Hermance  No.  40  —  12  and  16-inch. 

A  heavy  molder  that  combines  the  desirable 
features  of  both  the  inside  and  outsi'de  types.  No 
belts  on  working  side  allows  free  access  for  quick 
adjustments  and  easy  set-ups.  Has  the  massive 
frame,  rigid  bed  and  heavy  bearings  on  both  sides  of 
top  and  bottom  cutterheads  and  feed  rolls  that  are 
the  desirable  features  of  the  true  inside  molder. 
Hopper  feed  if  desired. 

Hermance  No.  50  —  8,  10  and  12-inch. 

Noted  for  remarkable  ease  and  speed  with  which 
set-ups  may  be  made,  due  to  its  accessibility  and 
the  simplicity  and  completeness  of  adjustment 
features,  making  it  an  exceptional  machine  for 
general  purpose  work.  May  be  equipped  with 
our  fast-feed  features,  which  are  of  unusual  sim- 
plicity. 

Hermance  6-inch  —  one,  two,  three  or  four  sided. 

An  ideal  machine  for  accurate  working  of  small 
moldings. 

Write  for  catalog  illustrating  and  fully  des- 
cribing our  line  of  modern  molders  and  other 
high-grade  wood-working  machinery. 

HERMANCE  MACHINE  CO. 

Williamsport,  Pa. 


170 


MACHINE  HOLDER  PRACTICE. 


a 

s 

CO 


1 

O 


MACHINE   HOLDER  PRACTICE.  171 

WOODS  No.  419  SUPER-SIX 
MOULDER 

THE  ONLY  MACHINE    OF  ITS  KIND  IN 

THE  WORLD  FOR  WORKING  THE 

LARGEST  AND  THE  HEAVIEST 

MOULDINGS  ACCURATELY 

AT  FAST  FEEDS 


The  most  complete  line  of 
moulders  manufactured  are 
made  by  The  S.  A.  Woods 
Machine  Co., Boston, U.S.  A., 
builders  of  wood-working 
machinery  since  1854. 

If  you  own  or  operate  a 
moulder,  ask  us  to  place  your 
name  on  our  mailing  list  to 
receive  our  moulding  publica- 
tions which  we  issue  from 
time  to  time. 

To  keep  in  close  touch 
with  this  progressive  manu- 
facturer of  fast-feed  moulders 
will  make  YOU  a  dominant 
factor  in  the  manufacture  of 
mouldings. 

S.  A.  WOODS  MACHINE  COMPANY 

BOSTON,  U:  S.  A. 


172 


MACHINE  MOLDER  PRACTICE. 


Woods  "Sawco"  Electric  Hand  Grinder. 


The  Woods  " Sawco"  Electric  Hand  Grinder  in  Operation. 


MACHINE   HOLDER   PRACTICE.  173 

WOODS  "SAWCO"  ELECTRIC 
HAND  GRINDER 

ONE  OF  WOODS  LABOR  AND 
TIME-SAVING  DEVICES 


Adapted  Especially  for  Moulding  Machine  Knives 


On  fast-feed  work,  where  formed  knives  are 
used,  this  grinder  is  indispensable.  It  will  elimi- 
nate almost  50%  of  the  time  lost  in  taking  care  of 
the  cutters.  After  a  formed  cutter  has  been  joint- 
ed several  times,  it  becomes  necessary  to  remove 
the  cutter-head  from  the  machine  and  take  the 
cutters  out  and  grind  off  the  heel.  This  not  only 
takes  a  great  deal  of  time  in  itself,  but  means  an 
equal  loss  of  time  in  re-setting  the  knives  in  the 
head  and  getting  the  head  back  into  the  machine. 
In  addition  to  this,  more  jointing  is  necessary  be- 
fore the  head  can  be  put  in  operation  with  the 
consequent  loss  of  time  and  expensive  high-speed 
steel.  The  SAWCO  grinder  will  eliminate  all 
of  this  and  the  heel  can  be  ground  off  of  the 
knives  without  taking  the  knives  out  of  the  head 
or  even  removing  the  head  from  the  machine  or 
disturbing  the  set-up  in  any  way. 

S.  A.  WOODS  MACHINE  COMPANY 

BOSTON,  U.  S.  A. 

The  History  of  the  Moulder  is  the  History  of  the  S.  A.  Woods  Machine  Co. 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 
BERKELEY 

Return  to  desk  from  which  borrowed. 
This  book  is  DUE  on  the  last  date  stamped  below. 


APR    61971 
REC'DLD 


AUG  2  9  198b 


% 

v 


ClRCULATi 


LD  21-100m-9,'47(A5702sl6)476 


6 


^s&Wmwli'^ 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


